Angelman syndrome

In about 1 percent of cases, Angelman syndrome is caused by an inherited abnormality in chromosome 15. In these cases, the chance of having another child with Angelman syndrome depends on the specific chromosome abnormality, and could be as high as 50 percent.^[1] A genetics professional can provide information on an individual's risk of having another child with Angelman syndrome.

Today there are a number of genetic tests that can be used to inform a couple about the possible outcomes of a current or future pregnancy. Examples of two such tests are prenatal diagnosis and preimplantation genetic diagnosis (PGD). Prenatal diagnosis can be used to diagnose a condition in a developing fetus. Today, doctors are able to diagnose many more birth defects than they are able to treat before birth. If a fetus has a condition for which prenatal treatment is not possible, prenatal diagnosis may help parents prepare emotionally for the birth and to plan the delivery with their health care providers.^[2] Parents can also use this information to make decisions regarding whether or not to continue the pregnancy. 

PGD represents an alternative to prenatal diagnosis.^[3] It is used following in vitro fertilization to diagnose a genetic disease or condition in embryos. Only embryos that do not carry the disease-causing mutation are implanted in the mother's womb. PGD allows testing to occur before a pregnancy begins.

In many cases, the disease-causing mutation must be identified in an affected relative before PGD or prenatal diagnosis can be performed.

You can learn more about these and other tests by visiting the links below to the view information on this topic developed by the Centre for Genetic Education and by the Genetics and Public Policy Center:
http://www.genetics.com.au/pntbooklet.pdf
http://www.dnapolicy.org/policy.issue.php?action=detail&issuebrief_id=7

Couples considering these options should talk with their healthcare provider and a genetic professional. It is important that couples are fully informed of the risks and benefits of each testing option and also have an opportunity to explore their feelings and beliefs regarding the use of these technologies. More information about genetic consultations is available from Genetics Home Reference at http://ghr.nlm.nih.gov/handbook/consult. To find a genetics clinic, we recommend that you contact your primary healthcare provider for a referral.

The following online resources can help you find a genetics professional in your community:  

• GeneTests has a searchable directory of US and international genetics and prenatal diagnosis clinics.
• The National Society for Genetic Counselors provides a searchable directory of US and international genetic counseling services.
• The American College of Medical Genetics has a searchable database of US genetics clinics.
• The University of Kansas Medical Center provides a list of US and international genetic centers, clinics, and departments.
• The American Society of Human Genetics maintains a database of its members, which includes individuals who live outside of the United States. Visit the link to obtain a list of the geneticists in your country, some of whom may be researchers that do not provide medical care.