Fast Five Quiz: Aromatic L-Amino Acid Decarboxylase Deficiency (AADCD)

Stephen L. Nelson, Jr, MD, PhD


August 05, 2021

Most patients with AADC deficiency have a severe phenotype with early-onset symptoms. Cases have been reported in the literature of patients with symptoms varying from mild (mild delay in developmental milestones, ambulation without assistance, and mild intellectual disability) to severe (no or very limited developmental milestones and full dependence upon others), with patients with moderate symptoms in between. Although no clear genotype/phenotype correlations have been defined, almost all severe cases have been linked to the founder splice variant IVS6 + 4A > T.

Signs and symptoms have most frequently been reported within the patient's first year of life. Despite the early onset of symptoms, the mean age of diagnosis from the cases reported in the literature was 3.5 years (median, 13 months; range, 2 months to 23 years).

Learn more about AADC deficiency phenotypes.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: