Stargardt disease

Stargardt disease is most commonly inherited in an autosomal recessive manner.^[1][2] This means that to be affected, a person must have a mutation in both copies of the responsible gene in each cell. Affected people inherit one mutated copy of the gene from each parent, who is referred to as a carrier. Carriers of an autosomal recessive condition typically do not have any signs or symptoms (they are unaffected). When 2 carriers of an autosomal recessive condition have children, each child has a:

• 25% (1 in 4) chance to be affected
• 50% (1 in 2) chance to be an unaffected carrier like each parent
• 25% chance to be unaffected and not be a carrier

A person with autosomal recessive Stargardt disease will always pass one mutated copy of the gene to each of his/her children. In other words, each of his/her children will at least be a carrier.  A child of an affected person can be affected if the other parent is also affected or is a carrier.

In rare cases, Stargardt disease may be inherited in an autosomal dominant manner.^[3] This means that having a mutation in only one copy of the responsible gene in each cell is enough to cause features of the condition. An affected person typically inherits the mutated gene from an affected parent.

When a person with a mutation that causes an autosomal dominant condition has children, each child has a 50% (1 in 2) chance to inherit that mutation.

While vision care and eye exams should be a part of every child's routine medical care,^[4] meeting with a specialist (such as an ophthalmologist or optometrist) is recommended for children with a family history of a genetic eye disease. A specialist can advise parents regarding if and when a child should be evaluated (and how often); and can recommend specific types of eye exams that may be beneficial or appropriate for children with a family history of Stargardt disease.

Stargardt disease is most commonly inherited in an autosomal recessive manner. Therefore in most cases, the child of a person with autosomal recessive Stargardt disease will be an unaffected carrier, and generally only at risk to develop the condition if their other parent is a carrier (or is affected). If an affected parent has autosomal dominant Stargardt disease (which is rare), each of his/her children has a 50% chance to inherit the mutated gene responsible for the condition.

Genetic testing for unsymptomatic minors (children who currently don't have symptoms) is usually not recommended for Stargardt disease and other genetic conditions that are not treatable.^[5]

Yes. Genetic testing may help distinguish the type of Stargardt disease a person has, and provide information about the mode of inheritance and risks to other family members. The Genetic Testing Registry (GTR) provides information about the genetic tests available for Stargardt disease. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about genetic testing for this condition should speak with their ophthalmologist or a genetics professional.

To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself. Online directories are provided by the American College of Medical Genetics and the National Society of Genetic Counselors. If you need additional help, contact a GARD Information Specialist. You can also learn more about genetic consultations from Genetics Home Reference.