AADC Deficiency and Ethnicity

Brian Murphy, Ph.D. avatar

by Brian Murphy, Ph.D. |

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ethnicity and AADC

Aromatic l-amino acid decarboxylase (AADC) deficiency is a very rare disease caused by mutations in the gene that encodes for the AADC protein. The disease seems to be more common in some parts of the world, and people of certain ethnicity may be at higher risk for the disease.

How do children inherit AADC deficiency?

To develop AADC deficiency, a child must inherit a faulty copy of the DDC gene from each parent. People with a single faulty copy of the gene generally do not have symptoms, but are carriers of the disease. If both parents are carriers, their children have a 25% chance of not inheriting the faulty gene from either parent, and not having the disease. They also have a 50% chance of inheriting the faulty gene from one parent, and becoming carriers themselves.

A child also has a 25% chance of inheriting a faulty copy from both parents and having AADC deficiency.

How does ethnicity affect AADC deficiency risk?

Although AADC deficiency is very rare, researchers have reported cases in several nations, including the U.S., Europe, Taiwan, and Japan. They also found cases among different ethnicities, including Asians, Caucasians, people of Middle Eastern descent, and African-Americans. However, around 20% of reported cases were among people of Taiwanese descent.

Who should be tested for AADC deficiency?

While AADC deficiency can affect a range of ethnicities, if you are of Taiwanese, Chinese, or Japanese descent, you may want to undergo genetic testing.

What if I am a carrier?

If you are an AADC deficiency carrier, you should talk to your partner about undergoing a genetic test before having children. If they are not a carrier, your children will not have AADC deficiency. However, they will have a 50% chance of being a carrier like you.

If your partner is also a carrier, your children have a 25% chance of having AADC deficiency. You may want to speak with a genetic counselor to discuss your options, and the possibility of lowering a risk of passing the disease to your children.


Last updated: Dec. 18, 2020


AADC 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.