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

Stephen L. Nelson, Jr, MD, PhD


August 05, 2021

The typical pattern of CSF in patients with AADC deficiency consists of low levels of 5-HIAA, HVA, and MHPG; normal level of pterins, including neopterin and biopterin; and high concentrations of 3-OMD, L-dopa, and 5-HTP. This pattern is indicative of a metabolic block at the level of AADC. Normal levels of pterins (neopterin, dihydrobiopterin, and tetrahydrobiopterin) are essential when differentiating between AADC deficiency and tetrahydrobiopterin disorders.

Although the CSF profile of patients with AADC deficiency may be similar to that of pyridox(am)ine 5-phosphate (PNPO) deficiency, low PNP levels and increased glycine and threonine indicate PNPO deficiency.

Learn more about the CSF pattern in patients with AADC deficiency.


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