Abstracts

Abstracts for Oral Presentations

Bioinformatics of Genetic and Translational Research
Peter J. Tonellato, Ph.D.
PointOne Systems, LLC.

There exists a pressing need to rapidly translate biomedical research discoveries to impact on human health care and use in medical practice. This issue is particularly urgent for rare diseases where the breakthroughs are more likely to have immediate impact at the clinical level. The multidisciplinary interactions of clinicians, biologists, genetics, new technology and bioinformatics has spurred a paradigm shift in our ability to create, use and exploit genomic and related biomedical resources and tools to conduct research into complex diseases. In the past ten years, the goal of whole genome sequencing has led to the convergence of various fields: mathematics, computer science, engineering, HPC and molecular biology generating data and information on over 100 genomes. This is just the beginning. New research paradigms will continue to generate massive amounts of data and correspondingly, produce important basic results at an accelerated rate. In addition, a new era of scientific perspective currently labeled “systems biology” is poised to consolidate this data and information to holistically understand biological systems. These activities mark the most exciting times in the history of basic biomedical research. The potential for applications in rare disease is enormous. PointOne Systems, LLC (www.pointonesystems.com), a molecular medicine company, uses bioinformatics and a strategic model for translation of the techniques and results in basic biomedical and biotechnology research to best practice health care. In this lecture, I will present the strategy, technology, and results of our efforts at one of the largest US heath care providers. In less than two years, our tools and methods have analyzed the clinical data and assessed the genetic status of more than 200,000 patients for cancer and cardiovascular disease. These results provide a comprehensive clinical review of the patients of more than 200 physicians and provide physician recommendations to design personalized health care for each patient based on the individual’s clinical and genetic medical profile. Our results have resulted in a new initiative we have formed with hospitals, research partners, and collaborators titled, “Molecular Medicine at the Point of Care.”

Pragmatic Language Issues in Children with Williams Syndrome
Carolyn B. Mervis, Ella Peregrine, & Melissa L. Rowe
Department of Psychological and Brain Sciences, University of Louisville

Children with Williams syndrome (WS) are consistently described as highly gregarious and extremely sociable. Most school-age children with WS have good vocabularies and speak fluently, with only occasional grammatical errors. Nevertheless, children with WS typically have problems forming reciprocal relationships, especially with peers. A likely reason for these difficulties is limitations in pragmatic skills. Addressing this possibility is challenging, however; adequate laboratory-based measures of pragmatic ability are not available. In this poster, we present findings from a new parent-report measure of communicative ability, the Children’s Communication Checklist—2nd edition (CCC-2; Bishop, 2003). This measure is designed to detect language impairment, including pragmatic impairment, in children ages 4 – 16 years who are consistently producing word combinations. The CCC-2 includes 10 7-item scales. Eight scales measure language structure, vocabulary, discourse, and pragmatic abilities. The last 2 scales measure behaviors that often are particularly impaired for children who have autism spectrum disorders. For the general population, each scale has a mean of 10 and SD of 3. The General Communication Composite (GCC) is the sum of the standard scores for the first 8 scales. We consider the performance of children with WS (current N: 37; mean CA: 8.94 years; mean KBIT IQ: 74.54) and their typically developing (TD) siblings (current N: 40; mean CA: 9.62 years) on the CCC-2, to begin to address the question of whether children with WS have significant pragmatic impairment. The standard scores for the WS group were significantly below those of the TD group on each of the 10 scales and the GCC (p<.001). The most dramatic differences were for the coherence, use of context, and inappropriate initiation scales. Correlations of verbal IQ, nonverbal IQ, and composite IQ with CCC-2 scales will be reported for the WS group. Preliminary findings suggest that in addition to more general weaknesses in language ability relative to siblings, children with WS have particular difficulties with the components of pragmatics and discourse that are most likely to impact on human relationships. This result offers a partial explanation for the difficulties children with WS have with inter-personal relationships, especially with peers, despite their eagerness to make and keep friends.

An Overview of Distal Trisomy 10q
Daryl Anderson
Distal Trisomy 10q Families

Distal Trisomy 10q is a chromosomal abnormality in which the individual has an additional fragment from the long arm of chromosome 10. It is characterized by facial dysmorphism, vision and hearing impairment, heart and kidney issues, as well as delays in mental and physical development. The syndrome is extremely rare with only about 60 surviving cases known within the literature and support groups. First described in 1965, there have been 48 papers written on the subject with the large majority being case studies. This presentation is based on a review of these papers and a survey (specifically for this study) of 12 individuals with the syndrome. The presentation will review the history of the syndrome, its frequency, how it occurs, its expression, the correlation between segments and symptoms, as well as treatments and therapies.

An uncertain future: Exploring the developmental consequences of rare chromosome disorders
Dr Linda Gilmore
Queensland University of Technology Brisbane, Australia
l.gilmore@qut.edu.au

This presentation explores current knowledge about the impact of rare chromosome disorders on cognitive functioning, social-emotional development and behavior. It is argued that, although knowledge about the physical and medical features associated with various chromosome anomalies is steadily accumulating, surprisingly little is known about developmental outcomes. Indeed, there are grounds for believing that the small number of published case reports does not accurately portray the range of developmental outcomes that may be achievable. Certainly the literature tends to paint an unduly pessimistic view of future development. Claims about the universal presence of characteristics such as mental retardation are seldom supported by convincing evidence, and relative strengths or typically progressing aspects of development are virtually never mentioned. Based on this literature, parents are often given unnecessarily negative prognoses for the future. In addition, families and professionals do not have access to reliable developmental information that is crucial for making decisions about the lives of individuals with rare chromosome disorders. These important issues are addressed during the paper. To illustrate the very different ways in which development may progress, two contrasting case reports of children with the same deletion, but very different developmental outcomes, are presented. Information about the speaker (if required) Dr Linda Gilmore is a developmental psychologist, lecturer and researcher who works with children with various disabilities and their families in Australia. She has a particular interest in the developmental consequences associated with rare chromosome disorders, and is writing on a book on this topic.

Abstracts for Poster Presentations

#1
Bioinformatics & Modeling to Detect Transitions from Health to Disease States
Nancy Laning Sobczak, Peter Tonellato
Marquette University Medical College of Wisconsin
sobczak2@execpc.com

The physiological and thus health “state” of an individual is composed of relatively simple biological building blocks put together in such a way as to create a complex organism capable of movement, expression, analytic processing, creativity, and procreation of life. These blocks consist of genes, gene expression, and proteins which result in biochemical processes. Operation of the biochemical processes manifest themselves via physiological parameters which can be measured. The observed values of these physiological parameters and their constituent parts can be used to demonstrate the states of the biological subject. In addition, these observations or measured parameters and the resulting states of the individual are further complicated by time dependent factors such as age of the biological subject and progression of disease within that subject. In this poster/paper we are developing a methodology that identifies the variations in susceptibility of the individuals to develop the disease, their progression of the subject through the disease process and the relative health status of the subject at any point in time. To do so, we propose a method that characterizes the resulting health states of the biological subject using the minimum, most relevant factors. We propose a “model” that combines genetic and physiological factors into one representation of the disease or medical state of an individual. That medical state vector can then be analyzed to produce and identify those factors and individuals who are most influenced by specific genes or genetic factors and or physiological or observed values. We will also show how the model accommodates the entire gamut of health status and disease states rather than merely providing a vehicle for the segregation of disease and non-diseased subjects. By merging of phenotypic and genomic factors we can create a model that attempts to characterize all the health states by dealing with factors that are known, hypothesized and yet to be discovered. Preliminary results demonstrate that a few variables typically provide the most information associated with the segregation of the population into different physiological states. Such approaches can be adapted to any disease of interest if the physiological and genetic observed values are available.

#2
Ocular Abnormalities in Apert Syndrome: Genotype/Phenotype Correlations with Fibroblast Growth Factor Receptor Type 2 Mutations
Terri L. Young, M.D.^1,2, David A. Young, M.D.¹, Jane C. Edmond, M.D.¹, Avrum Pollock, M.D.³, Donna M. McDonald-McGinn, M.S.², Elaine H. Zackai, M.D.²
1.Division of Pediatric Ophthalmology, The Children’s Hospital of Philadelphia, Philadelphia, PA 2.Division of Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA 3.Division of Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA
youngt@email.chop.edu

Abstract Introduction: Apert syndrome is a distinctive craniosynostosis disorder caused primarily by specific missense mutations involving adjacent amino acids (Ser252Trp or Pro253Arg) in the linker between the 2nd and 3rd extracellular immunoglobulin domains of the fibroblast growth factor receptor type 2 (FGFR2). We compared ophthalmic features in a cohort of Apert syndrome patients with known FGFR2 mutations. Methods: Retrospective chart review (17 patients). Results: Eleven of 17 had Ser252Trp substitutions. Of these, 11/11 had nasolacrimal duct obstruction (NLDO), 4/11 had manifest latent nystagmus (MLN), 8/11 had amblyopia, 8/11 had superior oblique muscle under-action (SOUA), and 9/11 had superior rectus muscle under-action (SRUA). Of those with Pro253Arg substitutions, 1/6 had NLDO, 0/6 had MLN, 2/6 had SOUA, and 2/6 had SRUA. Three patients with the Ser252Trp mutation had agenesis of the superior rectus and superior oblique muscles noted during intra-operative exploration. The degree and amounts of ptosis, refractive error, and other minor ophthalmic findings were similar between the two groups. Discussion: Apert syndrome patients with the Ser252Trp substitution appear to have a higher risk of NLDO, nystagmus, amblyopia, and vertical muscle dysfunction. An absent or anomalously positioned superior extra-ocular muscle complex may be more common with this mutation type. Conclusion: The two major FGFR2 mutation subtypes of Apert syndrome patients appear to show differences in frequencies of ophthalmic disease phenotypes.

#3
Neuroimaging in Down syndrome: what have we learned and where do we go from here?
Kristina Aldridge, Roger H. Reeves, and Joan T. Richtsmeier
Pennsylvania State University Johns Hopkins University School of Medicine
kja3@psu.edu

A substantial portion of the burden of care to families with a child with Down syndrome (DS) is due to the invariant presence of mental retardation and cognitive deficits that have been linked to anomalies in specific brain structures. The majority of brain development in humans occurs prenatally, which means that the developmental disturbances leading to brain anomalies in DS may occur before birth. Detailed information on prenatal brain structure and development cannot be studied in humans; instead, we turn to mouse models for Down syndrome. One such model, the Ts65Dn mouse has segmental trisomy for the distal end of mouse Chr 16. The distal Chr16 segment in Ts65Dn mice corresponds to a portion of Chr 21 that contains 118 of the 225 genes in the Chr 21 gene catalog. The genetic insult in these mice corresponds closely to that of segmental trisomy 21 in human beings. This mouse has been shown to display parallel cognitive and anatomical deficits to those seen in humans with DS. Studies of prenatal-aged mice are allowing us to determine the precise locations of these anatomicaldeficits, and the specific developmental timepoints when they occur. We will review what we have learned from neuroimaging studies about brain anomalies in humans with DS, what is known from mouse models for DS, and where the future of neuroimaging in DS will take us.

#4
Web-based Clinical Genetic Research and Disease Registry Environment
Zhitao Wang, Dan Chen, Bob Hedgcock, Drew Palin,M.D. and Peter Tonellato, Ph.D.
PointOne Systems, LLC

Modern Clinical research focuses an enormous amount of technology, funds and resources on identifying the genetic and related environmental factors important to the onset of the disease. In every study case, there is an urgent need for a high quality data collection, integration, and analysis resource available to the research program in a secure HIPAA compliant environment. This resource must be robust enough to hold the quantity and variety of clinical and pathologic data while at the same time being reliable enough to allow significant outcomes and validation studies. In efforts to meet this need, we have worked with an international collection of clinical genetic investigators to create a modularize resource adaptable to any clinical genetic study. This system is being used by 16 different clinical genetic research programs and currently is used to hold more than 300,000 subjects data. The information management system consists of three components: Pre-study, Registry, and Study. Each component is designed to meet the needs of the three fundamental stages of clinical genetic research programs.

#5
Anxiety and music in persons with Williams syndrome and other genetic disorders
Elisabeth M Dykens, Ph.D.
Vanderbilt Kennedy Center Vanderbilt University
elisabeth.dykens@vanderbilt.edu

Anxiety and music in persons with Williams syndrome and other genetic disorders From the ancient Greeks to the present, music has been shown to have a profound influence on mood and emotion. Persons with Williams syndrome have increased propensities for anticipatory anxiety and specific fears. Although less well-understood, many persons with this syndrome also show an attraction or affinity for music. This research is the first to compare music and anxiety in those with Williams syndrome. Specifically, this two-part study compares musicality in two samples of persons with Williams syndrome (total N = 57) to two other groups with mental retardation, and also relates music to anxiety and fears. Relative to those with either Prader-Willi syndrome (N = 46) or Down syndrome (N = 57), those with Williams syndrome were more likely to take music lessons, play an instrument, and have higher ratings of musical skills. In the Williams syndrome groups only, fewer externalizing symptoms were associated with listening to music, primarily aggression, while less anxiety and fewer fears were associated with the frequency, duration, and skill in producing music, and with emotional responses to negative-toned music. Implications are discussed for future research on anxiety and musical processing in Williams syndrome, and music as a means of decreasing anxiety and improving well-being in persons with this syndrome and other genetic disorders.

#6
Breakpoint mapping of Robertsonian translocations
Malgorzata Jarmuz (1), Kristen A. Bailey (1,2), Alberto L. Rosa (1,2), and Lisa G. Shaffer (1,2)
(1) Health Research and Education Center, Washington State University, Spokane, WA; (2) Sacred Heart Medical Center, Spokane, WA
jarmuz@wsu.edu

Occurring in ~1 in 1000 individuals, Robertsonian translocations (ROBs) are the most common chromosomal rearrangement in humans. Robertsonian translocations are formed through exchange of the short arms of the acrocentric chromosomes 13-15 and 21-22. Most Robertsonian translocations are dicentric and have lost the remainder of both short arms. Robertsonian translocations are considered balanced, and carriers have 45 chromosomes instead of the normal 46. The rearranged chromosomes involved in de novo nonhomologous ROBs are predominantly of maternal origin, suggesting a distinct mechanism involved in their formation. Carriers of balanced Robertsonian translocations are phenotypically normal because the short arms of the acrocentric chromosomes contain mostly tandemly repeated satellite DNA sequences and ribosomal RNA genes. However, carriers of balanced ROBs are at an increased risk of having chromosomally unbalanced, phenotypically abnormal offspring. These individuals are trisomic for one of the chromosomes involved in the translocation. The most common syndrome associated with ROBs and aneuploidy is Down syndrome. Approximately 5% of individuals with Down syndrome have rearrangements of chromosome 21; about half of these individuals have translocations involving chromosome 14, with some of the remainder carrying isochromosomes of the long arm of chromosome 21. Carriers of ROBs are also at an increased risk of uniparental disomy (UPD), the inheritance of both chromosome copies from a single parent. Uniparental inheritance of some chromosomes has been shown to be deleterious due to the effects of imprinting. In the present study we aim to map the breakpoint regions in the de novo rob(14q21q). These regions contain highly repetitive elements, which makes mapping difficult. However, we have selected several BACs which map to the short arm of the acrocentric chromosomes and have begun narrowing the breakpoint region in hybrids containing a rob(14q21q) by marker walking. By determining the breakpoint regions of Robertsonian translocations, we aim to elucidate factors that predispose certain parts of the genome to ROB formation.

#7
Microarray analysis uncovers complex rearrangements of 1p36 and results in identification of a putative gene for craniosynostosis
Marzena Gajecka (1), Wei Yu (3), Blake C. Ballif (1,3), Caron D. Glotzbach (1,2), Kristen A. Bailey (1,2), Chad A. Shaw (3), Catherine D. Kashork (3), Heidi A. Heilstedt (3), David A. Ansel (4), Aaron Theisen (1), Ritva Rice (5), David P.C. Rice (5), and Lisa G. Shaffer (1,2)
(1) Health Research and Education Center, Washington State University, Spokane, WA; (2) Sacred Heart Medical Center, Spokane, WA; (3) Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; (4) Department of Medicine, Children’s Hospital, Boston, MA; (5) Department of Craniofacial Development, King’s College, London
gajecka@wsu.edu

Monosomy 1p36 is a contiguous gene syndrome resulting from a heterozygous terminal deletion of the most distal chromosomal band on the short arm of chromosome 1. Monosomy 1p36 is the most commonly observed terminal deletion, occurring in ~1 in 5,000 births. Characteristic features of monosomy 1p36 include mental retardation, hearing impairment, heart defects, seizures, and growth impairment. In addition, the syndrome results in several distinct craniofacial features. We identified six subjects that have deletions, duplications, and/or triplications of 1p36. We performed array CGH and metaphase FISH analyses to confirm the deletion sizes. Additional FISH analysis for each subject confirmed the duplication and triplication sizes, established the order of the rearranged segments relative to the centromere, and elucidated the orientation of the segments relative to each other. By comparing the triplication sizes in the two subjects with complex rearrangements of 1p36 and craniosynostosis, we propose a 1.1 Mb critical region for a gene involved in cranial suture closure. By comparison with four other subjects with deletions of this critical region and large, late-closing anterior fontanels, we suggest that the gene, MMP23, which exists in two duplicated copies MMP23A and MMP23B on 1p36.3, is likely dosage-sensitive, which when overexpressed results in craniosynostosis and when haploinsufficient results in large, late-closing anterior fontanels. The expression pattern of Mmp23 in mouse calvarial sutures during embryonic development reveals that Mmp23 is expressed in the osteoblasts lining the calvarial bones, in the osteogenic fronts of the bones that are sites of active osteogenesis, and weakly in the suture mesenchyme. This expression pattern supports a role for Mmp23 in the regulation of calvarial suture development and fate (patent or ossified). Our results emphasize the continued important role of cytogenetics in investigating and uncovering the causes of human genetic disease, particularly the investigation of those cytogenetic imbalances that reveal potentially dosage-sensitive genes.

#8
Genetic Comorbid Syndrome Subtypes of Autism in Saudi Arabia
Stephen R. Schroeder, Ph.D., Pinar Ozand, M.D.,Ph.D., Brian Meyer, Ph.D.,Nadia Sakati, M.D., and Saleh Al Harbi, M.D.
University of Kansas, U.S.A., King Faisal Specialist Hospital and Research Centre, and King Fahd Medical City, Riyadh, Saudi Arabia
srs@ku.edu

Research on autism has grown at an exponential rate in the past decade. A major factor that allowed advancement of research in autism was a more accurate description of the genetic and behavioral phenotypes. The overlap of comorbid subtypes, such as tuberous sclerosis and Rhett Syndrome could be defined. Now a broad spectrum ofdevelopmental disorders, such as attention deficit disorder, language disorders, and learning disabilities are of intense interest for theirbehavioral, genetic and neurobiological overlap with autism. Thus, the heterogeneous features of autism and their gene-brain-behavior relationships are becoming better understood. Although 63 loci on the human genome have been considered at one time or another as linked to autism (Folstein and Sheidley, 2001), only a few associations have been verified by various groups of researchers. A large number of studies suggest that certain genes predispose the fetus to autism: 1. HOXA1 gene; 2. Reelin gene; 3.RAY1 gene; 4. Forkheadbox P2 gene;and 5. genes of the Disheveled Family of proteins. These genes are currently being studied intensively. We are currently doing a collaborative international study of comorbid features of Rhett Syndrome, tuberous sclerosis, and osteopetrosis with autism in large Saudi families and other Middle Eastern countries. This unique population is ideal for such studies because of the combination its high degree of consanguinity due to intermarriage going back 70 generations to the time of the Prophet Mohammed, the high genetic homogeneity and resulting incidence of birth defects, large intact family size, and marriage within tribes and within regions of the Kingdom. Often three or four probands are found in a single family. Current research progress will be

#9
Social Development of Children with Trisomy 18 and Trisomy 13 in the Context of Family and Community
Pamela J. Healey, Ph.D., Penny Hauser-Cram, Ph.D.
Boston College
Healeylex@aol.com

The influence of social support and positive thinking on parenting stress of 67 mothers and 51 fathers of 69 children and young adults ages one to early 20s with trisomy 18 and 13 and related disorders of the same chromosomes was examined. The influence of parental stress and parental resources on the child’s social development was then examined. Mothers and fathers reported significantly greater stress than parents of normally developing children. Mothers and fathers did not differ in the number in their social support network or in their perceived satisfaction with that support, although they differed in aspects that were helpful. Their own social support satisfaction did not explain levels of parenting stress, but the number in the fathers’ network related significantly to his child-related stress, and the fathers’ satisfaction with social support related significantly to the mothers’ child-related stress. Positive thinking about the child and the child’s condition related significantly to mothers’ parent-related stress. Aspects of positive thinking related to mothers’ child-related stress. Mothers’ positive reappraisal related to fathers’ child-related stress but not to her own. Differences by diagnosis were noted. Social development of the children occurred with age, significantly higher than other aspects of development and related to diagnosis. The development was not related to the stress levels of the parents, except for those with related disorders (mosaic, partial, translocation of trisomy 18 or 13), the highest functioning children. Parents’ social support and positive thinking related to the child’s social development. Children with trisomy 18 and trisomy 13 represent the genetic extreme and gave evidence of minimal transactional influence. Children with related disorders were higher functioning, and their development was significantly tied to parent functioning, indicating transactional influence.The children with full trisomy, as well as those with less than a full third chromosome in every cell, gave evidence of psychological development, including object permanence, mastery motivation, and increasing sense of self.

#10
Mechanisms of genomic disease
Pawel Stankiewicz¹ and James R. Lupski^1,2,3
1) Depts of Molecular & Human Genetics; 2) Pediatrics, Baylor College of Medicine, Houston, TX; 3) Texas Children Hospital, Houston, TX
pawels@bcm.tmc.edu

The term “genomic disorder” refers to a disease that is caused by an alteration of the genome that results in complete loss, gain, or disruption of the structural integrity of a dosage sensitive gene(s). In most of the common chromosome deletion/duplication syndromes, the rearranged genomic segments are flanked by large (usually>10kb), highly homologous low copy repeat (LCR) structures that can act as recombination substrates. Recombination between non-allelic LCR copies, also known as non-allelic homologous recombination (NAHR), can result in deletion or duplication of the intervening segment. Recent findings suggest that other chromosomal rearrangements, including reciprocal, Robertsonian, and jumping translocations, inversions, isochromosomes and small marker chromosomes, may also involve susceptibility to rearrangements related to genome structure or architecture. In several cases, LCRs, AT-rich palindromes and pericentromeric repeats are located at such rearrangement breakpoints. Analysis of the products of recombination at the junctions of the rearrangements reveals both homologous recombination and non-homologous end joining (NHEJ) as causative mechanisms. Homologous recombination appears to be the predominate mechanism. Thus, a more global concept of genomic disorders emerges in which susceptibility to rearrangements occurs due to underlying complex genomic architecture. Interestingly, this architecture plays a role not only in disease etiology through constitutional rearrangements, but also apparently in somatic rearrangement events associated with cancers and in primate genome evolution.

#11
Position effects due to chromosome breakpoints mapping ~ 1 Mb upstream and ~ 1.3 Mb downstream of SOX9 in two cases with campomelic dysplasia.
Pawel Stankiewicz(1), Gabriel Bien-Willner(1), James R. Lupski (1,2,3), Jill K. Northup (4), Lillian H. Lockhart (5), Syed M. Jalal (6), and Gopalrao V.N. Velagaleti (4,5)
1) Depts of Molecular & Human Genetics; 2) Pediatrics, Baylor College of Medicine, Houston, TX; 3) Texas Children Hospital, Houston, TX, 4Depts of Pathology and 5Pediatrics, University of Texas Medical Branch, Galveston, TX, 6Department of Pathology, Mayo Clinic, Rochester, MN.
pawels@bcm.tmc.edu

Campomelic dysplasia (CD) is a semilethal skeletal malformation syndrome with or without XY sex reversal. In addition to multiple mutations within the SOX9 gene on 17q24.3, several chromosome translocations and inversions with breakpoints scattered over 1 Mb upstream to SOX9 leading to haploinsufficiency have been described (Pfeifer et al. 1999). Here, we present an apparently balanced translocation t(4;17)(q28.3;q24.3), segregating in a family with a mild acampomelic CD and Robin sequence. Both breakpoints have been identified by FISH within single BAC clones. The 17q breakpoint maps ~ 1 Mb upstream of SOX9, within the same BAC clone as in the previously reported case. A somatic cell hybrid has been generated in our case and the breakpoint is being currently sequenced. DNA sequence analysis revealed a region conserved in human, chimpanzee, and mouse and candidate transcripts have been identified. Interestingly, Jamshidi et al. (2004) reported an isolated Robin sequence in a family segregating with a balanced translocation t(2;17)(q24.1;q24.3). The 17q breakpoint in this family maps very close to our breakpoint. We also report a prenatal identification of acampomelic CD with a male to female sex reversal in a fetus with a de novo apparently balanced complex karyotype 46,XY,t(4;7;8;17)(4qter->4p15.2::17q25->17qter;7qter->7p15::4p15.2->4pter;8pter->8q12.2::7p21.2->7pter;17pter->17q25::8q12.2->8qter). All breakpoints have been mapped within single BAC clones. Surprisingly, the 17q breakpoint maps ~1.3 Mb downstream of SOX9. This is the first report of CD with the chromosome breakpoint mapping distal to SOX9. We discuss the possible molecular mechanisms responsible for the position effect.

#12
Testing of Visual Acuity and Maximizing Visual Function in Subjects with Chromosomal Abnormalities
Hartnett, Mary Elizabeth, University of North Carolina
hartnet@med.unc.edu

Visual acuity is tested and measured based on the age and level of development in infants and children. In early development, vision is measured by the ability to detect light at different illumination levels in different fields of vision or as a quantitative measurement determined by the ability to discriminate different spatial frequencies. Age determined normative levels of quantitative acuity permit the assessment of visual development for age. At later ages, vision is tested by the child’s ability to determine forms, letters, and numbers. These tests correlate with later adult visual acuity. Most tests have been validated on developing infants and children and may provide reliable measurement of visual acuity and detection of developmental delays related to chromosomal disturbances. Quantitative visual testing also establishes a baseline to detect possible ocular disease, such as retinal detachment; to refine correction for refractive errors and maximize vision; and to determine the individual’s visual development curve. Specific ocular conditions have been associated with certain chromosomal conditions, including trisomy 21, 13, and 18. Extensive eye examinations, including vision testing, should also screen for specific abnormalities and are important in all evaluations. Maximal best-possible vision improves quality of life. Children with low vision adapt and use the vision they have better than adults who develop de novo similar levels of low vision in later life. A team of specialists—including the ophthalmologist, the low vision specialist, and vision educators—must set up an individualized management plan responsive to the needs of each patient for optimal patient management.

#13
Language profiles of young children with fragile X syndrome: Comparisons to autism and Down syndrome
Hepburn, S.L.¹, Philofsky¹, A., Rogers, S.J.^2, & Hagerman, R.J.²
1University of Colorado Health Sciences Center, 2University of California – Davis, M.I.N.D. Institute susan.hepburn@uchsc.edu

The purpose of this study is to examine the language profiles of young children with fragile X syndrome relative to children with other developmental disabilities (e.g., autism, Down syndrome) and typically-developing toddlers. Expressive and receptive language profiles of 78 2-3 year old children are examined using the Mullen Scales of Early Learning. Young children with fragile X syndrome showed two different language profiles – those with a comorbid diagnosis of autism showed marked deficits in both expressive and receptive functioning; those without autism demonstrated a significant strength in receptive language. These two profiles were similar to the two comparison groups (i.e., children with autism do not demonstrate a strength in receptive language and children with Down syndrome do). These findings suggests that children with comorbid fragile X and autism do not present with the strength in receptive language often reported in the literature on fragile X syndrome. Furthermore, information concerning early language functioning should be considered when determining whether a child with fragile X syndrome also has autism.

#14
Molecular Cytogenetic Identification of Chromosomal Imbalance in Prenatal and Pediatric Cytogenetics - the Contribution of Comparative Genomic Hybridization.
Brynn Levy, Nataline Kardon and Kurt Hirschhorn, Mount Sinai School of Medicine
brynn.levy@mssm.edu

The rapid advance of molecular cytogenetic technology has led to an increased number of referrals of specimens from patients with complex and unresolvable G-banded karyotypes to specialized laboratories. Defining the origin of unknown additional cytogenetic material with fluorescence in situ hybridization (FISH) by utilizing various probes is expensive and laborious as numerous whole chromosome paints (wcps) may be required until the source chromosome is identified. In addition, the number of available region specific probes is limited and covers only a fraction of the genome. Comparative genomic hybridization (CGH) is an alternative molecular cytogenetic technique that can characterize unbalanced and often unrecognizable G-banded cytogenetic material in a one-step global screening procedure. The advantage of CGH over conventional FISH with wcps and multicolor FISH is its ability to identify not only the chromosome from which the additional unknown material was derived but to also map the region involved to specific bands on the source chromosome. The ability of CGH to define more precisely the chromosomal material comprising chromosomal imbalance may help to further define critical chromosomal regions which are associated with normal and adverse phenotypic outcomes and thus provide prognostic information for genetic counseling. This information would directly benefit prenatally ascertained cases of marker chromosomes, providing couples with a means to make rational and informed decisions concerning the pregnancy. In pediatric cases, such information may provide the parents with a realistic prognosis and be important for the clinical management of the infant. In this report, we describe our approach to identifying chromosomal imbalances of unknown origin and indicate in which circumstances analysis by FISH or CGH is appropriate. We also review our 8 year experience with CGH in a clinical cytogenetic setting.

#15
Diagnosis and management of children with hearing loss
Charles i. Berlin, Ph.D., Bronya J.B.Keats, Ph.D.
LSU Health Sciences Center
Cberli@lsuhsc.edu

Phenotyping newborns with hearing losses can now be done within the first few days of life. There are four basic tests that can be used to determine the type and degree of the hearing loss as well as the parts of the ear that are not functioning normally: (1) Tympanometry (measuring middle ear mechanics); (2) Middle Ear Muscle reflexes (inferring synchrony of both afferent and efferent pathways as well as middle er integrity); (3) Otoacoustic Emissions (reflecting outer hair cell as well as middle ear integrity); and (4) Auditory Brainstem Responses (reflecting inner hair cell-to-nerve integrity). Differentiating anomalies of inner versus outer hair cells is particularly important because management differs drastically depending upon which hair cells are intact. There are also areas of the ear where mechanical obstruction can cause hearing loss. Examples of such areas are the pinna and external canal, the ossicular chain and related craniofacial structures, and the tympanic membrane. Performing these four tests provides critical data that are essential for accurate diagnosis and appropriate management. At least 50% of newborn hearing loss has a genetic etiology and it is a relatively common finding in children with aneusomies. Mutations in the GJB2 gene that encodes connexin 26 are the most frequent cause of genetic hearing loss in newborns, but mutations in more than 70 genes located throughout the genome are associated with hearing loss. It is likely that in some aneusomies one or more of these genes is affected. Thus, in the future the combination of genetic and auditory testing will enable precise diagnoses of hearing loss in children with aneusomies. Discriminating among etiologies of hearing loss using currently available auditory and genetic tests, and developing management tools, particularly for children with aneusomies, will be the focus of this presentation.

#16
Early Lexical Development and Later Language and Cognitive Abilities of Children with Williams Syndrome or Down Syndrome
Byron F. Robinson *, Carolyn B. Mervis**, Angela M. Becerra**, and Melissa L. Rowe**
*Department of Psychology, Georgia State University **Department of Psychological and Brain Sciences, University of Louisville
bfrobinson@gsu.edu

Williams syndrome (WS) is a contiguous gene disorder caused by a hemizygous submicroscopial deletion of chromosome 7q11.23. The typical cognitive profile of individuals with WS is associated with a relative strength in language and verbal memory ability. Children with Down syndrome (DS) typically display relatively delayed language skills and poor verbal memory. There is, however a significant amount of variability within, and some overlap between, the syndromes. To explore the bases of this variability we tracked the language and intellectual ability of 12 children with WS and 6 children with DS from the beginning of expressive language through at least 48 months of age. Of particular interest were the rate and shape of early lexical growth curves and their relations to later language and intellectual ability. Parents completed a vocabulary and grammar checklist every month. Children completed the Bayley Scales of Infant Development-II (BSID-II) at 24 months and the Differential Ability Scales (DAS) at 48 months of age. Significant and strong correlations were found between the age at which vocabulary size reached 10, 50, and 100 words; lexical growth rate; emergence of word combinations; BSID-II at 24 months; and DAS at 48 months. The two syndrome groups did not differ significantly on the DAS GCA and there was significant overlap in Verbal SS’s. In contrast, when the children were categorized based on the rate and shape of lexical growth, those with logistic growth (10 WS, 4 DS) performed significantly better than the linear growth group (2 WS, 2 DS) on all DAS measures. There was no overlap between the two growth curve groups in expressive vocabulary size or digit span. All children in the logistic group, but no child in the linear group, produced novel word combinations and had begun to produce bound morphemes productively by 48 months of age. These results suggest that the acquisition of first words sets in motion the process of language acquisition for both vocabulary and syntax, and that length of time to acquire first words may help set the rate of development for vocabulary, grammar, and more general aspects of intellectual ability.

#17
Mapping structural differences of the corpus callosum in individuals with 18q deletions using targetless regional spatial normalization.
Peter Kochunov, PhD*, Jack Lancaster, PhD*, L. Jean Hardies, PhD*, Jannine D. Cody, PhD**, Daniel E. Hale, MD**, Angela Laird, PhD*, Peter T. Fox, MD*
*Research Imaging Center, **Department of Pediatrics, The University of Texas Health Science Center at San Antonio
kochunov@uthscsa.edu

Individuals with a constitutional chromosome abnormality consisting of a deletion of a portion of the long arm of chromosome 18 (18q-) have a high incidence (~95%) of dysmyelination. Neuroradiological findings in affected children report smaller corpora callosa (CC), but this finding has not been quantified. This is in part due to a large anatomical variability in size and shape of CC and a small number of subjects with 18q-, which leads to low statistical power for comparison with children with normal chromosomes who are developing typically.
A novel analysis method called Targetless Spatial Normalization (TSN) was employed to improve the sensitivity of statistical testing. TSN consists of global and regional steps that converge all images in the group into the group common space. The group common space conserves the common shape, size, and orientation while reduces intra-group variability. TSN in conjunction with Witelson vertical partitioning scheme was used to assess difference in CC size between twelve children with 18q-, for whom reduced gene copy number of myelin basic protein gene has been verified, and twelve age-matched normal controls. Significant global and regional CC differences were discovered. Globally, the group with 18q- showed an overall smaller CC (p<10-7) even after correction for global brain size. Regionally, the posterior portions of CC (posterior midbody, isthmus and splenium), which contain heavily myelinated fibers were found to be significantly smaller (p<0.05) in the population with 18q-.

#18
The Spectrum of Thyroid Abnormalities in Individuals with 18q Deletions.
Rebecca L. Schaub, MS*, Daniel E. Hale, MD*, Susan Rose, MD**, Robin J. Leach, PhD*, Jannine D. Cody, PhD*
*Department of Pediatrics, The University of Texas Health Science Center at San Antonio
**Division of Endocrinology, Cincinnati Children’s Hospital Medical Center and University of Cincinnati, OH
hale@uthscsa.edu
   Chromosome 18q deletions are common survivable autosomal deletions, having an estimated incidence of 1/40,000 live births. Our primary goals are to 1) comprehensively define the endocrine phenotype, 2) determine the natural history and 3) identify the key genes leading to a particular phenotype. Medical record review and comprehensive clinical assessments have been performed on 120 individuals with 18q deletions, the largest group of individuals with 18q- ever assembled. Affected subjects ranged in age from 6 weeks to 32 years at initial assessment. Due to case reports of thyroid dysfunction in 18q deletions, and the well-established association between hypothyroidism and aneusomies, we undertook thyroid testing in all individuals and completed thyrotropin releasing hormone studies on 50 of them. Our studies demonstrated that 12% had hypothyroidism and the results were consistent with primary thyroidal dysfunction. Furthermore, 2 individuals progressed from normal to abnormal over the course of 2 years. Based on these studies, it appears that annual thyroid testing is indicated for all individuals with 18q deletions.

#19
Identification of Critical Regions for the 18q- Phenotype.
Jannine D. Cody, PhD*, Ales Dostal, PhD*, Patricia Heard, BS*, AnaLisa Duran, BS*, L. Jean Hardies, PhD**, Jack Lancaster, PhD**, Brian Perry, MD*, William Beck, PhD***, Douglas Hoffman, MD***, Robert F. Stratton, MD*, Rebecca L. Schaub, MS*, Peter T. Fox, MD**, Celia I. Kaye, MD*, Daniel E. Hale, MD*
*Department of Pediatrics, **Research Imaging Center, and *** Otolaryngology, The University of Texas Health Science Center at San Antonio
cody@uthsca.edu

Constitutional chromosome abnormalities are biologically complex while genetically simple. They are complex because they involve hundreds of genes and simple because these genes are contiguous. Our goal is to identify specific genes associated with distinct phenotypic features in individuals with 18q deletions. Here we describe the first step in this process, the identification of small chromosomal regions associated with several phenotypic features. The identified regions are associated with growth hormone deficiency, dysmyelination of the brain, cleft palate, kidney malformation, aural atresia, proximally placed thumbs and midfacial hypoplasia.

#20
Myelination in Children with Partial Deletions of Chromosome 18q.
Jack L. Lancaster PhD*, Jannine D. Cody, PhD**, Trevor Andrews MS*, L. Jean Hardies PhD*, Daniel E. Hale, MD**, Peter T. Fox MD*
*Research Imaging Center, **Department of Pediatrics, The University of Texas Health Science Center at San Antonio
jlancaster@uthscsa.edu

   Myelin levels in white matter (WM) of typically developing children were compared with those of children with partial deletions of chromosome 18q (18q-). Conventional spin-echo MR imaging at 1.9 Tesla was used to acquire T1 weighted, proton density weighted, and T2 weighted images o f the brain. From these images a three-pool model was used to estimate the fraction of water in myelin, myelinated axon, and mixed water compartments (or pools) in six WM regions. Water-pool fractions in children with 18q- ranging in age from 5 months to 13 years were compared with those of age-range matched typically developing children.
   In the children with 18q- the myelination model predicted later onset of myelination (p<0.02), lower myelination rates (p<0.001), and smaller equilibrium myelin pool fractions (p<0.001). Significant differences were seen between the two groups of children for all three water pool fractions (p<0.001). The mixed pool fraction was larger in the children with 18q-. Both myelin (my) and myelinated axon (ma) pools were smaller in the children with 18q-, and the myelin per myelinated axon ratio (my/ma pool fraction ratio) was significantly smaller in the children with 18q- (p<0.001). The level of myelin in children with 18q- is less than 50% that of age matched typically developing children.

#21
Clinical Features of Individuals with Tetrasomy 18p.
Elizabeth R. Roeder, MD, Rebecca L. Schaub, MS, AnaLisa Duran, BS, Patricia Heard BS, Daniel E. Hale, MD, Jannine D. Cody, Ph.D.
Division of Genetics and Metabolic Disorders, Department of Pediatrics, The University of Texas Health Science Center at San Antonio
roeder@uthscsa.edu

Tetrasomy or isochromosome 18p is characterized by low or normal birth weight, developmental delay/mental retardation, microcephaly, dysmorphic features, scoliosis, camptodactyly, hypotonia and/or spasticity. Seizures and structural malformations including minor congenital heart defects and renal anomalies occur in less than one-fourth of affected individuals. Tetrasomy 18p usually arises as a de novo event with only 3 familial cases in the literature.
In this study we present clinical information on 21 individuals with tetrasomy 18p. Participants were recruited from the Chromosome 18 Registry and Research Society or were referred by their local physician. Inclusion criteria for the protocol were tetrasomy 18p and willingness to send medical records and/or blood samples on the proband and parents.   One individual with tetrasomy 18p mosaicism was excluded from this review. Parental chromosomes obtained in 9 of the cases were normal. The initial phase of the project has included review of available records and molecular analysis of the samples from 15 families.
   The age of the 21 participants ranges from 2 to 24 years and includes 14 females and 7 males. Average birth weight was 2.9 kg. Feeding difficulty and jaundice occurred frequently during the neonatal period. Commonly reported features included microcephaly, small, round face, epicanthal folds, small, upturned nose, small ears and mouth, highly arched palate, altered palmar creases, camptodactyly, clinodactyly, scoliosis, kyphosis and foot deformities. Anomalies consisted of minor congenital heart defects, cryptorchidism, horseshoe kidney, spina bifida, Arnold-Chiari malformation and hypoplastic corpus callosum. GE reflux and constipation occurred frequently. Abnormal white matter signal intensity on MRI was reported in 5 cases. All individuals experienced developmental delay and have cognitive impairment with most in the moderate to severe range. Neurological and ocular abnormalities were common and consisted of seizures, hypotonia, spasticity, strabismus, astigmatism and optic nerve atrophy. Chronic otitis media occurred in 3/4 of the participants and approximately 1/3 had hearing loss. Postnatal growth has been adequate in the majority with 10% having a weight at or below the 5th centile and 5% with a height at or below 5th centile. Growth hormone deficiency was documented in 2 cases. Behavioral issues included ADHD, obsessive-compulsive tendency, autistic-like behavior and aggressiveness.
   Our preliminary molecular analysis shows that the isochromosomes do not contain 18q material and therefore are not dicentric consistent with other studies. Experiments using quantitative PCR and molecular cytogenetics to determine the content of each arm of the isochromosome are in progress which will hopefully provide insight into the mechanism of isochromosome 18p formation. This survey is preparatory to comprehensive on-site clinical evaluations. We are currently enrolling additional participants for this clinical and molecular study. Additional information is available at www.pediatrics.uthscsa.edu/chromosome18/.

#22
Life and Health Outcomes in Adults with Deletions of Chromosome 18
C.I. Kaye, J.D. Cody, R. L. Schaub, R.J. Leach, and D. E. Hale
Department of Pediatrics, The University of Texas Health Science Center at San Antonio
kaye@uthscsa.edu

Numerous individuals with deletions of 18q and 18p have been described in the medical literature. The previously reported cases consist mostly of children who were severely affected. There is little information about outcomes in adulthood for individuals with these conditions. The Chromosome 18 Clinical Research Center at the University of Texas Health Science Center at San Antonio performs comprehensive and longitudinal studies of individuals with chromosome 18 abnormalities. Although we have focused on enrolling children, we have enrolled adults, and some of the children we were following are now adults. We have reviewed our data on the 14 individuals in our study who have 18q- or 18p- and are 18 years of age or older. All of these individuals are female. Although there is a very wide range in their abilities, many of the adults are living a more functional life than would have been predicted for them when they were children. Although some individuals with 18q- have virtually no independent living skills, most have completed high school and live independently. All of the individuals in our study with 18p- graduated from high school or will achieve this goal soon. Sexual maturity for both groups appears to be normal and several have had children.

#23
The 18q- Phenotype: Based on a Comprehensive Clinical Assessment of 90 Individuals
Cody, JD*, Schaub RL*, Semrud-Clikeman M**, Hardies LJ***, Lancaster J***, Fox PT***, Beck WG****, Stratton RL*, Leach RJ*, Kaye CI*, Hale DE*
*Department of Pediatrics, ***Research Imaging Center, and ****Department of Otolaryngology, The University of Texas Health Science Center at San Antonio
**Department of Educational Psychology, The University of Texas at Austin
cody@uthscsa.edu

Deletions of chromosome 18q are among the most common of the survivable autosomal deletions; with an estimated incidence of 1/40,000 live births. Our primary goals are to comprehensively define the phenotype and determine the natural history. The ultimate goal of this work is to identify the key genes that lead to each of the phenotypic components. Ninety individuals have provided extensive medical records and have participated in a comprehensive clinical assessment at The Chromosome 18 Clinical Research Center; many have been seen 2 or more times. This is the largest group of individuals with this condition assessed by a single group of investigators. Affected individuals range in age from 6 weeks to 32 years. We have performed the following studies: auxology, endocrinologic testing, magnetic resonance brain imaging, audiologic examination, neurologic assessment, neuropsychological appraisal and psychiatric evaluation. We have found a very wide range of physical and performance characteristics in these individuals. The most common features are dysmyelination of the brain (97%), expressive speech delay (91%), hypotonia (79%), foot deformities (74%), hearing loss (70%) and short stature (68%). Both cross-sectional and longitudinal natural history data have been gathered from medical record review from seeing a large group of individuals from a wide range of ages and repetitive visits to our Center. For example, the 10 adult females ranging in age from 20 to 47 years have a much better academic outcome than might be predicted from their early childhood assessments. Nine of ten completed high school in an academic program and two are currently college students. However, the majority have bipolar affective disorder which require medical management. Most of the phenotypic features can be associated with specific regions of hemizygosity. For example, performance IQ scores range from immeasurably low to above average (120). About 10% of individuals have IQ of less than 40: this lower IQ is associated with the deletion of a region at 18q21.2. Additionally, 2 MB critical regions for growth hormone deficiency and CNS dysmyelination have been identified at 18q23. Candidate genes in these critical regions are being assessed.

#24
Increases in Growth and Intelligence in Individuals with 18q- who are Treated with Growth Hormone
J.D. Cody*, R.L. Schaub*, M. Semrud-Clikeman**, J.G. Baillargeon*, R.J. Leach*, C.I. Kaye*, D.E. Hale*
*Department of Pediatrics, The University of Texas Health Science Center at San Antonio
**Department of Educational Psychology, The University of Texas at Austin
cody@uthscsa.edu

Most individuals with deletions of chromosome 18q have growth failure and mental retardation. We evaluated 20 individuals with terminal deletions of 18q, 10 of whom qualified for growth hormone replacement therapy. We evaluated the participants longitudinally for changes in growth and performance intelligence quotient (IQ). The average time interval between evaluations was 37 months, and the average age of the participants was 44 months at the beginning of this study. Over the course of the study, the untreated group failed to have a significant change in performance IQ scores. The treated group had mixed results. However, there was a correlation between the size of the deletion and the change in IQ. Three of the four individuals who had no performance IQ increase had the largest terminal deletions. The individuals who had a performance IQ increase, had an average increase of 16 points. An IQ change of this magnitude is highly significant (p=0.002). The entire treatment group, regardless of the size of deletion, also had significant catch-up growth in comparison to the untreated group who maintained their height standard deviation scores.

#25
Cognitive Ability and Adaptive Behavior Associated with Extent of Deletion in Children with 18q Deletions.
Margaret Semrud-Clikeman, PhD*, Nora M Thompson, Ph.D**, Becky L Schaub, MS***, Robin Leach, PhD***, Andrea Hester, MA*, Daniel E Hale, MD***, Jannine D. Cody, PhD***
*Department of Educational Psychology, The University of Texas at Austin, Austin, TX
**Division of Psychiatry and Behavioral Health Sciences, University of Washington, Seattle, WA
***Department of Pediatrics, The University of Texas Health Science Center at San Antonio, San Antonio, TX
peg.semrud@mail.utexas.edu

Individuals with a constitutional chromosome abnormality consisting of a deletion of a portion of the long arm of chromosome 18 (18q-) have a high incidence (~95%) of dysmyelination. Neuroradiological findings in affected children report smaller corpora callosa (CC), but this finding has not been quantified. This is in part due to a large anatomical variability in size and shape of CC and a small number of subjects with 18q-, which leads to low statistical power for comparison with children with normal chromosomes who are developing typically.
A novel analysis method called Targetless Spatial Normalization (TSN) was employed to improve the sensitivity of statistical testing. TSN consists of global and regional steps that converge all images in the group into the group common space. The group common space conserves the common shape, size, and orientation while reduces intra-group variability. TSN in conjunction with Witelson vertical partitioning scheme was used to assess difference in CC size between twelve children with 18q-, for whom reduced gene copy number of myelin basic protein gene has been verified, and twelve age-matched normal controls. Significant global and regional CC differences were discovered. Globally, the group with 18q- showed an overall smaller CC (p<10-7) even after correction for global brain size. Regionally, the posterior portions of CC (posterior midbody, isthmus and splenium), which contain heavily myelinated fibers were found to be significantly smaller (p<0.05) in the population with 18q-.