chr7-66082880-G-T

Variant names:

• chr7-66082880-G-T
• rs770375565
• NM_000048.4:c.292G>T

Variant summary

Our verdict is Pathogenic. Variant got 20 ACMG points: 20P and 0B. PVS1 PM2 PP3_Moderate PP5_Very_Strong

The NM_000048.4(ASL):​c.292G>T​(p.Glu98*) variant causes a stop gained, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,518 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: ASL NM_000048.4 stop_gained, splice_region
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 8.78

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 20 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
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 7-66082880-G-T is Pathogenic according to our data. Variant chr7-66082880-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 553428.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ASL	NM_000048.4	c.292G>T	p.Glu98*	stop_gained, splice_region_variant	Exon 5 of 17	ENST00000304874.14	NP_000039.2
ASL	NM_001024943.2	c.292G>T	p.Glu98*	stop_gained, splice_region_variant	Exon 4 of 16		NP_001020114.1
ASL	NM_001024944.2	c.292G>T	p.Glu98*	stop_gained, splice_region_variant	Exon 4 of 15		NP_001020115.1
ASL	NM_001024946.2	c.292G>T	p.Glu98*	stop_gained, splice_region_variant	Exon 4 of 15		NP_001020117.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ASL	ENST00000304874.14	c.292G>T	p.Glu98*	stop_gained, splice_region_variant	Exon 5 of 17	1	NM_000048.4	ENSP00000307188.9

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000120 AC: 3 AN: 250554 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135706

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: 0.0000265

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461518 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727046

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.00000809

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.000106 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Argininosuccinate lyase deficiency Pathogenic:2

Nov 15, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Glu98*) in the ASL gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ASL are known to be pathogenic (PMID: 2263616, 24166829). This variant is present in population databases (rs770375565, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with argininosuccinate lyase deficiency (PMID: 24166829). ClinVar contains an entry for this variant (Variation ID: 553428). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Aug 18, 2017

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	51
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	1.0	D
Vest4		0.89
GERP RS		5.3

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.51		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.26		Position offset: 3
DS_AL_spliceai		0.51		Position offset: 0

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

Publications

LitVar

Other links and lift over

dbSNP: rs770375565; hg19: chr7-65547867;