18p- Basics
18p- is a genetic condition where part of the short arm (p arm) of chromosome 18 is missing. This deletion can result in various health issues and developmental delays. Each case of 18p- is unique, and the symptoms and severity can vary greatly among individuals. Common challenges include developmental delays, often in the mild range, and potential health problems like heart defects, hormone issues, and neurological concerns. The condition is usually diagnosed through a blood test in infants or children exhibiting health and developmental concerns. The Chromosome 18 Registry & Research Society provides support and resources for families dealing with 18p-.
For a more comprehensive understanding of 18p-, please click on links referring to the detailed information provided in the 18p (English) or 18p- (Spanish) PDF handouts that are downloadable and printable items.
Recently Diagnosed with 18p-? Visit UT Health Clinical Management Guides page for more information.
Basics
Just Diagnosed with 18p-?
Receiving a diagnosis of 18p- can be a very difficult and confusing experience for families. Although it may explain why a child has medical problems or developmental delays, it also brings a lot of new questions. The good news is that we know a lot about 18p-, and we are continuing to learn more through the ongoing research at the Chromosome 18 Clinical Research Center.
On this page, we are going to answer the most common questions parents have when their child is first diagnosed with 18p-. More detailed information is available and can be found by clicking the links within the text on this page.
We also encourage you to speak with a genetics provider in your area to learn more about what this diagnosis means for you and your family.
What is 18p-?
18p- happens when part of the short arm of one of the two copies of chromosome 18 is missing. This means there is one copy instead of two for each of the genes in the deleted region of the chromosome.
Learn more about the genetic basis of 18p-
What causes 18p-?
18p- occurs when a piece of chromosome 18 is lost. This change likely occurred in the egg or sperm prior to conception or very shortly after conception. There is no known cause of 18p-.
How is 18p- diagnosed?
18p- is usually diagnosed when an infant or child has health and/or developmental concerns. Most often, the diagnosis is made by a blood test. This test looks at the chromosomes to see whether a piece of chromosome is missing.
Learn more about how 18p- is diagnosed
What health problems are associated 18p-?
18p- can cause several different kinds of birth defects. Heart defects and a certain kind of brain malformation, known as holoprosencephaly, occur in some people with 18p-. They may also have some problems in the newborn period, such as feeding or breathing difficulties. As they get older, they may develop other health problems. For example, people with 18p- are at risk for hormone issues, such as thyroid problems and growth hormone deficiency. Other health concerns may include vision problems, foot problems, and neurological issues, such as seizures or a movement disorder. There are other health problems that have been reported in people with 18p-, but these are the most common.
There is a great deal of variability among people with 18p-. At this point in time, it is impossible to predict exactly how it will affect an individual. However, knowing this diagnosis helps families and their health care team know what to look out for.
Learn more about the health of people with 18p-
Are there any concerns for development in people with 18p-?
Almost all children with 18p- have developmental delays, usually in the mild range. This means that they may not meet their milestones on time, though they do usually achieve them. For example, they often roll over, walk, and talk later than other children. Nearly all people with 18p- have some intellectual or learning disability. This means they will have more difficulty learning and developing new skills. The degree of intellectual disability varies greatly between different people with 18p-.
What do the genes on chromosome 18 do?
There are 67 genes on chromosome 18p. They play various roles in a person’s growth, development, and overall health. Currently, research is focused on understanding how missing specific genes on chromosome 18p lead to health and developmental concerns. We know that many of the genes on 18p do not cause problems when one copy is missing. However, there are a handful of genes that we think may be associated with specific features.
Learn more about genes of interest on 18p
What can I expect for my child with 18p-?
It is difficult to predict exactly how a person’s life will be affected by a deletion of 18p. However, we know that children with 18p- go to school, develop new skills, make friends, and are members of their communities.
What should I do for my child with 18p-?
Every child with 18p- is different. However, we can make some recommendations for evaluations to ensure that the most common concerns are identified and addressed early. The Chromosome 18 Clinical Research Center has created an “18p- Management Guide”. We strongly recommend reviewing this document with your physician for additional details and information about managing 18p-. Some of the management recommendations include the following:
Immediate Referrals to:
- Genetics
- Early Intervention
One Time Evaluations:
- Echocardiogram
- Abdominal ultrasound
Annual Screenings:
- Thyroid
- Ophthalmology
- Hearing
Closely Monitor:
- Growth
- Allergy symptoms
- Changes in neurological status
- Behavioral & mood concerns
Depending on a person’s health concerns, additional screenings or management strategies may be necessary. It is important to discuss a health care plan with your team of healthcare providers.
What research is being done?
The Chromosome 18 Clinical Research Center is dedicated to fully understanding the chromosome 18 conditions as well as to developing treatments for these conditions. For additional information or to enroll in the study, please visit their website.
Where can I go for more support and information?
The Chromosome 18 Registry & Research Society is dedicated to making chromosome 18 conditions the first treatable chromosome abnormalities. We count within our membership thousands of parents, siblings, extended family and friends, businesses, and affected individuals. Registry membership is open to any interested person.
We invest in both people and science; supporting our members through education and a sense of community while also focusing squarely on impactful clinical research that will lead to healthier, happier, and more independent lives for those affected and their families.
There is a great deal of additional information on our website, as well as the opportunity to connect with other parents. To become a member, please go to our home page and click the “become a member” Green button on menu.