7-66082420-A-G

Position:

• chr7-66082420-A-G

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_Very_Strong

The ENST00000304874.14(ASL):​c.260A>G​(p.Asp87Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,459,796 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. D87D) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ASL ENST00000304874.14 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 8.30

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 16 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 3 uncertain in ENST00000304874.14
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 7-66082420-A-G is Pathogenic according to our data. Variant chr7-66082420-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 557253.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-66082420-A-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ASL	NM_000048.4	c.260A>G	p.Asp87Gly	missense_variant	4/17	ENST00000304874.14	NP_000039.2
ASL	NM_001024943.2	c.260A>G	p.Asp87Gly	missense_variant	3/16		NP_001020114.1
ASL	NM_001024944.2	c.260A>G	p.Asp87Gly	missense_variant	3/15		NP_001020115.1
ASL	NM_001024946.2	c.260A>G	p.Asp87Gly	missense_variant	3/15		NP_001020117.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ASL	ENST00000304874.14	c.260A>G	p.Asp87Gly	missense_variant	4/17	1	NM_000048.4	ENSP00000307188	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000812 AC: 2 AN: 246284 Hom.: 0 AF XY: 0.00000750 AC XY: 1 AN XY: 133324

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: 0.0000180

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1459796 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 725988

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Argininosuccinate lyase deficiency Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jan 31, 2024	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Mar 14, 2018	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 27, 2023	This sequence change replaces aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 87 of the ASL protein (p.Asp87Gly). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with argininosuccinic aciduria (PMID: 12384776, 24166829). ClinVar contains an entry for this variant (Variation ID: 557253). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ASL protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects ASL function (PMID: 11747433). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.61
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;.;D;D;.
Eigen	Pathogenic	0.87
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	.;D;D;D;D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	H;H;H;.;H
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-6.7	D;D;D;D;D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D
Polyphen		1.0	D;.;D;.;.
Vest4		0.99
MutPred		0.96		Loss of stability (P = 0.0465);Loss of stability (P = 0.0465);Loss of stability (P = 0.0465);.;Loss of stability (P = 0.0465);
MVP		0.99
MPC		0.82
ClinPred		1.0	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.96

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs752100894; hg19: chr7-65547407;