Madisons Foundation - Moms And Dads In Search Of Needed Support

What

Holt Oram syndrome is a rare genetic condition that is characterized by arm bone malformations and heart defects. Bone and arm abnormalities may affect each arm differently and the left side is usually affected more than the right side. How an individual is affected with this disorder and how severe signs and symptoms are can vary a great deal.

Who

This condition affects males and females equally. Exactly how often this syndrome occurs is not known, but it is estimated to occur in about 1 out of every 100,000 births. 60% of affected individuals have an affected parent.

Signs and Symptoms

Signs and symptoms of this syndrome include; 1. congenital heart defects: The most common heart defects are atrial septal defects (ASD) and ventricular septal defects (VSD). An ASD is a hole in the wall between the atria, which are the two upper chambers of the heart. A VSD is a hole in the wall between the ventricles, which are the two lower chambers of the heart. Ventricular septal defects are found in 5-20% of the patients. Other heart defects can be found as well. 2. Thumb abnormality: The thumb can be missing or formed more like a finger. The thumb can have an extra bone and this makes it look more like a finger. 3. Limb malformations: • webbing of the thumb with the forefinger (syndactyly) • curving of the fifth finger towards the ring finger (clinodactyly) • abnormally formed, missing or additional bones in the wrist; partial or complete absence of bones in the forearm • underdevelopment of upper arm bone (humerus) 4. Heart conduction problems: There is a risk for heart conduction problems even when there are no other heart abnormalities. 5. Other bone abnormalities: Especially collarbones and shoulder blades

Possible Causes

The genes associated with Holt Oram syndrome are located on chromosome 12. Genetic changes in two different genes have been linked to this disorder. These two genes are for transcription factors, which play a role in arm development. This syndrome is inherited in autosomal dominant manner with almost half of cases being new genetic changes. It is thought that new changes result in more severe symptoms than cases where a genetic change has been inherited from a parent.

Diagnosis

The diagnosis of Holt Oram syndrome is made by finding the above described signs and symptoms on physical examination. Imaging studies, such as X-rays, can be useful in detecting bone abnormalities. The findings of underdevelopment of the wrist bones or the presence of additional bones in the wrist are two of the most useful hints for clinicians in making the diagnosis. In order to evaluate for heart defects, studies like electrocardiographs (EKG) or echocardiograms may be done.

Treatment

Treatment of this condition is focused to the specific symptoms in an individual, so children with extremely mild forms of HOS1 may not require any intervention. In other cases, surgery for correction of limb defects may be useful. If a heart defect is present, medical treatment may be necessary. Treatment options vary from medications and diet control to surgery depending on severity of the symptoms and any associated inability to function normally. Physical and/or occupational therapy is also beneficial in many cases.

Prognosis

Since there is a wide range of symptoms with this disorder it is difficult to predict what the future holds for each child. However, many children with this condition grow up to lead normal lives and have children of their own. There has been great advancement in the treatment of congenital heart disease and children with heart defects can do very well after surgery.

Connect with other parents

In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease, please fill out this brief form.

Weblinks

Contact A Family- for Families with Disabled Children
This site has a forum for parents, including a separate page for fathers. It provides some medical information, but mainly it tries to connect parents of children with similar disorders. There is a separate section for rare diseases.

Congenital Heart Information Network
Site has a lot of valuable information, links, discussion forums and addresses of local support groups organized by State/country.

Helping Hands Foundation
Resources, information and support for families of children with upper limb abnormalities.

Google Search for Holt Oram Syndrome

References and Sources

Holt Oram Syndrome www.thefetus.net/page.php?id=1144 OMIM: Holt Oram Syndrome www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=142900