Abstract: Objective　To report clinical manifestations and genetic characteristics of 2 cases with aromatic L-amino acid decarboxylase deficiency (AADCD). Methods　Clinical data and genetic results of two cases with AADCD were collected and analyzed, and related literature was reviewed. Results　Both cases were female, and the main clinical manifestations were feeding difficulty, backward motor development, nystagmus and convulsion. Genetic test found patient 1 carried compound heterozygous mutation c.1234C>T in the exon 13 and c.170 A > G (p.I57T) in DDC, and patient 2 carried compound heterozygous mutation c.1234C>T in the exon 13 and c.179 T > C (p.V60A) in DDC. In addition, c.170 A > G (p.I57T) and c.179 T > c (p.V60A) were novel variants with unknown significance. Conclusion　These two AADCD children both had typical clinical manifestations. The disease was rare and complex, and early diagnosis is helpful to improve prognosis.

Key words: aromatic L-amino acid decarboxylase deficiency; AADC deficiency; gene mutation; DDC gene