Summary
To confirm a diagnosis of AADC deficiency, at least two out of three of the following diagnostic tests should be positive, and genetic testing should be performed:2
- Low CSF levels of 5-HIAA, HVA, and MHPG, increased CSF levels of 3-OMD, L-Dopa, and 5-HTP, and normal levels of CSF pterins
- The presence of compound heterozygous or homozygous pathogenic variants in the DDC gene
- Decreased AADC enzyme activity in the plasma
- If genetic testing is performed as the first step, functional confirmation should be completed by AADC enzyme plasma testing and CSF neurotransmitter metabolites panel2
- Chien YH, et al. Mol Genet Metab. 2016;118:259‒263.
- Wassenberg T, et al. Orphanet J Rare Dis. 2017;12:12.
- IEMbase© Inborn Errors of Metabolism Knowledge base. Aromatic L-amino acid decarboxylase deficiency. Available at: http://iembase.org/app/#!/disorder/100. Last accessed February 2021.
- Himmelreich N, et al. Mol Genet Metab. 2019;127:12‒22.
- Pearson, TS, et al. J Inherit Metab Dis. 2020;43:1121–1130.
- Dai W, et al; on behalf of the Mainland Chinese League of AADC Rare Disease. Mol Genet Genomic Med. 2020;8:e1143.
- Monteleone B, Hyland K. BMC Neurol. 2020;20.
- Micallef J, et al. Neuropediatrics. 2020;51:229‒232.
- Brennenstuhl H, et al. Neuropediatrics. 2019;50:2‒14.