Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2
The NM_000666.3(ACY1):c.1001T>C(p.Met334Thr) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,878 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).
ACY1 (HGNC:177): (aminoacylase 1) This gene encodes a cytosolic, homodimeric, zinc-binding enzyme that catalyzes the hydrolysis of acylated L-amino acids to L-amino acids and an acyl group, and has been postulated to function in the catabolism and salvage of acylated amino acids. This gene is located on chromosome 3p21.1, a region reduced to homozygosity in small-cell lung cancer (SCLC), and its expression has been reported to be reduced or undetectable in SCLC cell lines and tumors. The amino acid sequence of human aminoacylase-1 is highly homologous to the porcine counterpart, and this enzyme is the first member of a new family of zinc-binding enzymes. Mutations in this gene cause aminoacylase-1 deficiency, a metabolic disorder characterized by central nervous system defects and increased urinary excretion of N-acetylated amino acids. Alternative splicing of this gene results in multiple transcript variants. Read-through transcription also exists between this gene and the upstream ABHD14A (abhydrolase domain containing 14A) gene, as represented in GeneID:100526760. A related pseudogene has been identified on chromosome 18. [provided by RefSeq, Nov 2010]
ABHD14A-ACY1 (HGNC:38856): (ABHD14A-ACY1 readthrough) This locus represents naturally occurring read-through transcription between the neighboring abhydrolase domain containing 14A (ABHD14A) and aminoacylase 1 (ACY1) genes on chromosome 3. The read-through transcript encodes a protein that shares sequence identity with the downstream gene product but its N-terminal region is distinct due to the use of an alternate start codon relative to the upstream gene. [provided by RefSeq, Oct 2015]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
Occurs in the last base pair of the exon Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Aminoacylase 1 deficiency Uncertain:1
Dec 15, 2016
Mayo Clinic Laboratories, Mayo Clinic
Significance: Uncertain significance
Review Status: criteria provided, single submitter