Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_StrongPM2
The NM_000666.3(ACY1):c.19G>T(p.Glu7*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,394 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.
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]
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.985 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;