AADC Deficiency and the Heart

As a very rare genetic medical condition affecting the nervous system,  aromatic l-amino acid decarboxylase (AADC) deficiency can have a wide range of symptoms, including movement disorders, oculogyric crises and, in rare instances, heart problems.

What is AADC deficiency?

AADC deficiency is caused by mutations in the DDC gene, which contains the blueprint for cells to make an enzyme called aromatic l-amino acid decarboxylase (AADC). The body uses the AADC enzyme to produce dopamine and serotonin, two very important molecules for transmitting signals in the nervous system. Mutations in the DDC gene lead to a lack of AADC enzyme and therefore decreased levels of dopamine and serotonin. This ultimately leads to symptoms affecting the nervous system.

What are the heart issues in AADC deficiency?

AADC deficiency is exceptionally rare, with only about 100 documented cases in the medical literature. Due to its rarity, most studies that discuss heart symptoms are case studies of one or two individuals. As such, they may not be representative of all AADC deficiency patients.

Some cases in the literature with heart-related issues include one patient with bradycardia (slower than normal heart rate) and a patient, age 9, who had a heart attack.

Possible causes of heart issues in AADC deficiency

The exact link between AADC deficiency and cardiac complications is not clear. Researchers think these may be due to problems with the autonomic nervous system. The autonomic nervous system controls many unconscious body functions including breathing, blood pressure, and heart rate. The lack of dopamine and serotonin may disrupt the function of the nerve cells of the autonomic nervous system. Cardiac complications may be more evident if patients are sick or in stressful situations as this could further affect the autonomic nervous system.

Some medications for AADC deficiency also could lead to heart problems. Doctors may prescribe patients dopamine receptor agonists (medications that imitate dopamine) to help treat symptoms of AADC deficiency. However, some of those medications can lead to fibrosis (scarring) around the heart tissue and valves, which could lead to problems in the future.

What precautions are necessary?

It is important to be aware that AADC deficiency patients may have cardiac complications, especially in stressful situations. It also is important to monitor the heart before anesthesia. So, physicians should be made aware that the patient has AADC deficiency and apprised about the medications they are taking.

Last updated: Dec. 2, 2020

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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 health provider 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.