The targeting construct inserted C890T base pair subsitution (S250F)) in exon 7 followied by a self-excising ACN cassette (tACE-Cre/Neo) flanked by loxP sites. The mutation was confirmed by sequencing. The second most commonly reported genetic lesion in AADC deficiency (infant Parkinsonism) is associated with a C835T missense mutation (S250F amino acid alteration) in exon 7 of the human DDC (AADC) gene. (J:250494)