Fast Five Quiz: Aromatic L-amino Acid Decarboxylase Deficiency (AADCD) Clinical Characteristics

Stephen L. Nelson, Jr, MD, PhD


August 13, 2021

Aromatic L-amino acid decarboxylase deficiency (AADCD) is a disorder of the pathogenic DDC gene, which encodes the AADC enzyme. AADCD is a rare, autosomal recessive neurometabolic disorder characterized by a severe deficiency of serotonin, dopamine, norepinephrine, and epinephrine. Fewer than 150 cases have been described in the literature to date. There is an increased prevalence in patients of southern Chinese descent, particularly those from Taiwan and Japan. Onset is usually during infancy.

The two most common symptoms of AADCD are hypotonia in the trunk and oculogyric crises. In addition, dysfunction of the autonomic nervous system can lead to symptoms such as hypersalivation, ptosis, nasal congestion, temperature instability, hypotension, and hypoglycemia. AADCD should be considered in children with hypotonia, movement disorders, developmental delay, excessive sweating, and autonomic symptoms without other plausible causes of such characteristics.

How much do you know about the clinical characteristics of AADCD deficiency? Test your knowledge with this quick quiz.


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