6-131573340-G-T

Variant names:

• chr6-131573340-G-T
• rs587776539
• NM_000045.4:c.57+1G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_000045.4(ARG1):​c.57+1G>T variant causes a splice donor, intron change. The variant was absent in control chromosomes in GnomAD project. 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 Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: ARG1 NM_000045.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.97
• Publications: 0 publications found

Genes affected

ARG1 (HGNC:663): (arginase 1) Arginase catalyzes the hydrolysis of arginine to ornithine and urea. At least two isoforms of mammalian arginase exist (types I and II) which differ in their tissue distribution, subcellular localization, immunologic crossreactivity and physiologic function. The type I isoform encoded by this gene, is a cytosolic enzyme and expressed predominantly in the liver as a component of the urea cycle. Inherited deficiency of this enzyme results in argininemia, an autosomal recessive disorder characterized by hyperammonemia. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2011]

ARG1 Gene-Disease associations (from GenCC):

• arginase deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Myriad Women’s Health, Orphanet, ClinGen, G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.11764706 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 6-131573340-G-T is Pathogenic according to our data. Variant chr6-131573340-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 2102477.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ARG1	NM_000045.4	c.57+1G>T		splice_donor_variant, intron_variant	Intron 1 of 7	ENST00000368087.8	NP_000036.2
ARG1	NM_001244438.2	c.57+1G>T		splice_donor_variant, intron_variant	Intron 1 of 7		NP_001231367.1
ARG1	NM_001369020.1	c.57+1G>T		splice_donor_variant, intron_variant	Intron 1 of 5		NP_001355949.1
ARG1	NR_160934.1	n.114+1G>T		splice_donor_variant, intron_variant	Intron 1 of 6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ARG1	ENST00000368087.8	c.57+1G>T		splice_donor_variant, intron_variant	Intron 1 of 7	1	NM_000045.4	ENSP00000357066.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Arginase deficiency Pathogenic:1

Mar 06, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This sequence change affects a donor splice site in intron 1 of the ARG1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in ARG1 are known to be pathogenic (PMID: 7649538, 12052859). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with arginase deficiency (PMID: 7649538). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	33
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.0
GERP RS		6.0
PromoterAI		-0.58	Under-expression
Mutation Taster		=1/99	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: -1

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

Other links and lift over

dbSNP: rs587776539; hg19: chr6-131894480;