Autosomal recessive
Caused by changes in both copies of ACY1, which encodes the enzyme aminoacylase 1. Loss of the enzyme leads to raised levels of N-acetylated amino acids in urine, which is how the condition is detected.
Signs and symptoms
Reported features vary widely and include developmental delay, low muscle tone, movement problems, mild intellectual disability and seizures. Some people identified through urine testing or family studies have had no symptoms, so it remains unclear how much of the reported illness is caused by the enzyme deficiency itself.
What a diagnosis changes
Care is guided by any symptoms present. Urine testing can confirm the biochemical deficiency. Both parents of an affected child are usually carriers, so further children may be affected; genetic counselling and carrier testing of relatives are available.
Genes analysed
Also known as
ACY1 deficiency; ACY1D; deficiency of the aminoacylase-1 enzyme; N-acyl-L-amino acid amidohydrolase deficiency; neurological conditions associated with aminoacylase 1 deficiency
