Genetic Counseling for Families Affected by AADC Deficiency

If you or a family member has a genetic disease like aromatic L-amino acid decarboxylase (AADC) deficiency, you might benefit from genetic counseling.

What is genetic counseling?

If you have AADC deficiency, genetic counseling can help you understand whether you are at risk of passing this disease to your children. Your primary care physician can help put you in contact with a genetic counselor.

If someone in your family  has AADC deficiency,  you may be a carrier of the disease. Carriers of genetic diseases generally do not have symptoms themselves but can transmit the disease to their children. The genetic counselor can review your family’s medical history, and help you determine whether you should be genetically tested to determine your carrier status.

If you have already been tested and are a disease carrier, a genetic counselor can go over the results with you and explain what they mean.

Many people speak to a genetic counselor when they are considering starting a family. The counselor can talk with you about the risk of your child inheriting AADC deficiency. They can also go through your options to reduce that risk, such as considering in vitro fertilization with a pre-implantation genetic diagnosis.

How do people inherit AADC deficiency?

AADC deficiency is caused by mutations in a gene called dopa decarboxylase (DDC), located on chromosome 7. Both men and women with a mutated DDC gene can pass it to their children.

To develop AADC deficiency, a child must inherit two copies of a disease-causing mutation (one from each parent). This is called recessive inheritance.

What happens if I test positive for AADC deficiency?

If you test positive for AADC deficiency, you are a carrier for this disease and you should meet with a genetic counselor and your doctor. They will explain the results of your genetic test, and discuss whether other family members may need to be tested.

If your partner is not a carrier of AADC deficiency, your children will have a 50% chance of inheriting a faulty copy of the AADC deficiency-causing gene from you. In this case, they will also be a carrier like you. They will have a 50% chance of inheriting the healthy copy of the gene. In this case, they will neither have the disease nor be a carrier.

If your partner is also a carrier of AADC deficiency, your children will have 25% chance of inheriting the mutated gene from both of you and developing AADC deficiency. They  have 50% chance of inheriting a faulty copy of the gene from either you or your partner, and being a carrier. Finally, they will have 25% chance of inheriting a healthy copy of the gene from both of you. In this case, again, they will neither have the disease nor be a carrier.

What happens if I test negative?

A negative genetic test result, especially when other family members test positive, can sometimes leave a person feeling anxious or depressed, a type of “survivor’s guilt.”

If you are feeling guilty, ashamed, or sad after a negative test, you may need to talk to a genetic counselor, your doctor, or a therapist.

Last updated: July 8, 2020

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ADC News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare providers with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.