We hope to provide you with support and understanding, and share what we know as we learn more about this very rare syndrome. If you are interested in looking at more photos of our children, they are available at the website described on the last page.
Costello syndrome is a rare multiple congenital anomaly disorder in which individuals have characteristic craniofacial features, failure to thrive, ectodermal and musculoskeletal anomalies, cardiac abnormalities, endocrinopathy, developmental delay and a predisposition to neoplasia,* both benign and malignant. [Estep et al, 2006]
[* malignant tumors]
A detailed review on the management of Costello syndrome can be found here: http://www.ncbi.nlm.nih.gov/books/NBK1507/
If you have not yet had your child tested for the HRAS mutations, we strongly recommend that you do! One reason is because for some, it’s hard to tell if the child has Costello syndrome or one of the other “RASopathies”, and while they share some issues, there are issues that are unique to each syndrome. For instance, children with Costello syndrome have the highest risk of cancer among the RASopathies. Testing will also help researchers looking for clues about how the different mutations on the HRAS gene work.
In the United States, insurance companies usually approve a doctor’s request for the test, and in most states, Medicaid will pay for it too. A list of clinical laboratories that do the test can be found at www.genetests.org/
In the UK and Europe please discuss genetic testing with your doctor who will make arrangements for the testing to be carried out.
Because our children’s syndrome is so extremely rare, it would be unusual for people to consider Costello syndrome prenatally if it was the first child, but there are labs that will test prenatally.
If you have not had genetic counselling, we urge you to ask your child’s doctor for this service. Your having a child with a rare genetic condition makes you eligible for this service. Next are basic questions about Costello syndrome that would be fleshed out in a genetics counselling appointment:
Because our children’s syndrome is so extremely rare, it would be unusual for people to consider Costello syndrome prenatally if it was the first child, but there are labs that will test prenatally. If you have not had genetic counselling, we urge you to ask your child’s doctor for this service. Your having a child with a rare genetic condition makes you eligible for this service. Next are basic questions about Costello syndrome that would be fleshed out in a genetics counselling appointment:
Q: What are my chances of having another child with Costello syndrome?
A: Your chances of having another child are low. No one on our listserv of about 200 members have had another child with Costello syndrome. Researchers know that Costello syndrome is autosomal dominant, meaning that it affects the HRAS gene mutation on one copy of chromosome 11. This can happen a few ways:
- The child inherits a mutation from one parent – who also has the syndrome. In our case, this means that if your child with Costello syndrome has children, your grandchild has a 50% chance of having Costello syndrome. There are no known children who have inherited Costello syndrome this way.
- The child inherits a mutation from one parent – who doesn’t have the syndrome but has a mutation in the reproductive system (sperm or egg) that developed when the child was in the womb. This is called mosaicism, and is very rare, even for Costello syndrome! The most effective way to consider this kind of mutation transmission is if there are siblings with Costello syndrome in the family – learning from the siblings, rather than being able to test for it. There are only two known sets of siblings with Costello syndrome, in old publications, but they have not been tested for the Hras mutation, so we’re still not sure.
- The child developed the mutation while in the womb – spontaneously (spontaneous mutation). This is the most likely way that your child developed Costello syndrome. Spontaneous mutations in general are not uncommon. Most do not survive past the first few weeks of conception – most pregnancies do not survive past the first trimester, and often times, the mother doesn’t even know she’s pregnant.