rs796051933

chr7-66089675-GGCGTCATCTCTAC-G

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000048.4(ASL):c.1045_1057del(p.Val349CysfsTer72) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000824 in 1,613,750 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. G348G) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000088 (0 hom.)
• Consequence: ASL NM_000048.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 7.94

Genes affected

ASL (HGNC:746): (argininosuccinate lyase) This gene encodes a member of the lyase 1 family. The encoded protein forms a cytosolic homotetramer and primarily catalyzes the reversible hydrolytic cleavage of argininosuccinate into arginine and fumarate, an essential step in the liver in detoxifying ammonia via the urea cycle. Mutations in this gene result in the autosomal recessive disorder argininosuccinic aciduria, or argininosuccinic acid lyase deficiency. A nontranscribed pseudogene is also located on the long arm of chromosome 22. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-66089675-GGCGTCATCTCTAC-G is Pathogenic according to our data. Variant chr7-66089675-GGCGTCATCTCTAC-G is described in ClinVar as [Pathogenic]. Clinvar id is 203629.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-66089675-GGCGTCATCTCTAC-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ASL	NM_000048.4	c.1045_1057del	p.Val349CysfsTer72	frameshift_variant	14/17	ENST00000304874.14
ASL	NM_001024943.2	c.1045_1057del	p.Val349CysfsTer72	frameshift_variant	13/16
ASL	NM_001024944.2	c.985_997del	p.Val329CysfsTer72	frameshift_variant	12/15
ASL	NM_001024946.2	c.967_979del	p.Val323CysfsTer72	frameshift_variant	12/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ASL	ENST00000304874.14	c.1045_1057del	p.Val349CysfsTer72	frameshift_variant	14/17	1	NM_000048.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152188 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000735

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000359 AC: 9 AN: 250612 Hom.: 0 AF XY: 0.0000442 AC XY: 6 AN XY: 135720

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000707

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000876 AC: 128 AN: 1461562 Hom.: 0 AF XY: 0.0000880 AC XY: 64 AN XY: 727098

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000111

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000329 AC: 5 AN: 152188 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74342

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000735

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000434 Hom.: 0

Bravo AF: 0.0000227

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Argininosuccinate lyase deficiency Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 28, 2023	This sequence change creates a premature translational stop signal (p.Val349Cysfs*72) in the ASL gene. RNA analysis indicates that this premature translational stop signal induces altered splicing and likely results in a shortened protein product. This variant is present in population databases (rs762010471, gnomAD 0.006%). This premature translational stop signal has been observed in individuals with argininosuccinate lyase deficiency (PMID: 1705937, 16941645, 24166829). ClinVar contains an entry for this variant (Variation ID: 203629). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this premature translational stop signal affects ASL function (PMID: 31943503). Studies have shown that this premature translational stop signal results in skipping of exon 14 (also known as exon 13), but is expected to preserve the integrity of the reading-frame (PMID: 16941645). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Sep 09, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Aug 01, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jun 16, 2021	Variant summary: ASL c.1045_1057del13 (p.Val349CysfsX72) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 3.6e-05 in 250612 control chromosomes (gnomAD). c.1045_1057del13 has been reported in the literature in multiple individuals affected with Argininosuccinic Aciduria (Barbosa_1991, Walker_1997, Beck_2011, Balmer_2014, Zielonka_2020). These data indicate that the variant is very likely to be associated with disease. At least one publication reports this deletion apparently causes exon skipping (Barbosa_1991). Four submitters (evaluation after 2014) cite the variant as pathogenic (n=3) and likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as pathogenic. -

Neurodevelopmental disorder Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory of Molecular Genetics (Pr. Bezieau's lab), CHU de Nantes

Mar 08, 2023

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Mar 21, 2022

Gel-based analysis of mRNA derived from patient fibroblast cells harboring c.1045_1057del found that this variant frequently results in exon skipping (Barbosa et al. 1991); Frameshift variant predicted to result in protein truncation, as the last 116 amino acids are replaced with 71 different amino acids, and other loss-of-function variants have been reported downstream in the Human Gene Mutation Database (HGMD); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 9045711, 21710918, 31943503, 1705937) -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs796051933; hg19: chr7-65554662;