aminoacylase 1 deficiency aminoacylase 1 deficiency aminoacylase 1 deficiency is a rare inborn error of metabolism. to date only 21 cases have been described. aminoacylase 1 deficiencyother namesneurological conditions associated with aminoacylase 1 deficiencyaminoacylase 1 deficiency is inherited in an autosomal recessive manner signs and symptoms the clinical picture is heterogeneous and includes motor delay, seizures, moderate to severe mental retardation, absent speech, growth delay, muscular hypotonia and autistic features. genetics this disorder in inherited in an autosomal recessive fashion. molecular biology aminoacylase 1 (acy1: ec 3.5.14) is a zinc binding enzyme which hydrolyzes n-acetyl amino acids into the free amino acid and acetic acid. of the n-acetyl amino hydrolyzing enzymes, aminoacylase 1 is the most common. the acy1 gene is located on the short arm of chromosome 3 (3p21.2). diagnosis there is a specific pattern of n-acetyl amino acid excretion in the urine. the diagnosis can be confirmed by sequencing of the aminoacylase 1 gene. treatment history this disorder was first reported in 2005.