Aminoacylase 1 deficiency is a rare inborn error of metabolism.

[1][2] The clinical picture is heterogeneous and includes motor delay, seizures, moderate to severe mental retardation, absent speech, growth delay, muscular hypotonia and autistic features.

[citation needed] This disorder in inherited in an autosomal recessive fashion.

[citation needed] The ACY1 gene is located on the short arm of chromosome 3 (3p21.2).

[citation needed] There is a specific pattern of N-acetyl amino acid excretion in the urine.