The following information may help to address your question:
What causes CHARGE syndrome?
CHARGE syndrome is caused by mutations
in the CHD7
gene in the majority of cases. Almost all mutations in affected individuals are de novo, which means they occur for the first time as new mutations and are not inherited from a parent. However, autosomal dominant
inheritance with transmission from parent to child has been reported in rare cases.
gene provides instructions for making a protein that most likely regulates gene activity (expression). Most mutations in the CHD7
gene lead to the production of an abnormally short, nonfunctional CHD7
protein, which is thought to disrupt the regulation of gene expression. Changes in gene expression during embryonic development likely cause the signs and symptoms of CHARGE syndrome.
About one-third of individuals with CHARGE syndrome do not have an identified mutation in the CHD7
gene. The cause is unknown in these individuals, but researchers suspect that other genetic and/or environmental factors may be involved.
Last updated: 3/8/2013
Is CHARGE syndrome inherited?
CHARGE syndrome is usually not inherited, typically occurring due to a new (de novo
) gene mutation in the affected individual. However, rare familial cases inherited in an autosomal dominant
manner have been described.
To our knowledge, all individuals who have a CHD7
mutation have some features of CHARGE syndrome (i.e. penetrance
is 100%). In rare instances, one parent may have mild features, and the family history may appear to be negative because of failure to recognize the mild features of the condition.
The risk to the siblings of an affected individual depends on the genetic status of the individual's parents. If a parent of an affected child also has CHARGE syndrome, the risk for each sibling to inherit the condition is 50%. If neither parent is affected, the risk to each sibling of an affected child is estimated to be 1%-2%, most likely attributable to germline mosaicism
. Prenatal diagnosis
for pregnancies at increased risk is possible if the disease-causing CHD7
mutation has been identified in an affected family member.
Last updated: 3/11/2013
Is genetic testing available for CHARGE syndrome?
Genetic testing is available for CHARGE syndrome. The CHD7
gene is the only gene in which mutations are known to cause CHARGE syndrome. The CHD7
mutation detection rate when sequence analysis
is performed is estimated to be 65%-70% for all typical and suspected cases combined.
GeneTests lists the names of laboratories that are performing clinical genetic testing for CHARGE syndrome. To view the contact information for these laboratories, click here
. Please note that most of the laboratories listed through GeneTests do not accept direct contact from patients and their families. Therefore, if you are interested in learning more, you will need to work with a health care provider or a genetics professional.
Last updated: 3/11/2013
How can I find a genetics professional in my area?
Last updated: 7/15/2016
We hope this information is helpful. We strongly recommend you discuss this information with your doctor. If you still have questions, please
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