rs372128852

Positions:

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_054012.4(ASS1):c.970+5G>A variant causes a splice donor 5th base, intron change. The variant allele was found at a frequency of 0.0000161 in 1,613,932 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

ASS1
NM_054012.4 splice_donor_5th_base, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:11

Conservation

PhyloP100: 5.54

Variant links:

Genes affected

ASS1 (HGNC:758): (argininosuccinate synthase 1) The protein encoded by this gene catalyzes the penultimate step of the arginine biosynthetic pathway. There are approximately 10 to 14 copies of this gene including the pseudogenes scattered across the human genome, among which the one located on chromosome 9 appears to be the only functional gene for argininosuccinate synthetase. Mutations in the chromosome 9 copy of this gene cause citrullinemia. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Aug 2012]

ASS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

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 9-130489469-G-A is Pathogenic according to our data. Variant chr9-130489469-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 265962.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-130489469-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ASS1	NM_054012.4 linkuse as main transcript	c.970+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000352480.10
ASS1	NM_000050.4 linkuse as main transcript	c.970+5G>A		splice_donor_5th_base_variant, intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ASS1	ENST00000352480.10 linkuse as main transcript	c.970+5G>A		splice_donor_5th_base_variant, intron_variant		1	NM_054012.4	P1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152118

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251104

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135848

show subpopulations

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:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000164

AC:

AN:

1461814

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

727214

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000189

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152118

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74284

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000615

Hom.:

Bravo

AF:

0.00000756

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:11

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Citrullinemia type I

Pathogenic:8

Likely pathogenic, no assertion criteria provided	clinical testing	Counsyl	Mar 31, 2017	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	3billion	Jan 03, 2022	The variant has been reported at least twice as pathogenic/likely pathogenic with clinical assertions and evidence for the classification (PMID_11941481, ClinVar ID: VCV000265962). The variant has been reported to be in trans as homozygous in at least one similarly affected unrelated individual (PMID: 7557970, PM3_P). In silico prediction tools predicted that this variant influenced pre-mRNA splicing, resulting in aberrant splicing (SPLICEAI: 0.92>=0.8, PP3_P). It is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.000018, PM2_M). Therefore, this variant is classified as likely pathogenic according to the recommendation of ACMG/AMP guideline. -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jan 12, 2024	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Oct 31, 2018	- -
Pathogenic, no assertion criteria provided	literature only	GeneReviews	Sep 01, 2016	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Mar 11, 2021	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Apr 01, 2002	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 02, 2020	Variant summary: ASS1 c.970+5G>A alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Four predict that the variant abolishes or weakens a 5' splicing donor site. At least one publication reports experimental evidence that this variant affects mRNA splicing (e.g. Kobayashi_1995). The variant allele was found at a frequency of 1.6e-05 in 251104 control chromosomes (gnomAD). c.970+5G>A has been reported in the literature in multiple individuals affected with Citrullinemia Type I (e.g. Kobayashi_1995, Haberle_2002, Gao_2003, Diez-Fernandez_2016). These data indicate that the variant is very likely to be associated with disease. Four other clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Citrullinemia

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 12, 2023

This sequence change falls in intron 13 of the ASS1 gene. It does not directly change the encoded amino acid sequence of the ASS1 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs372128852, gnomAD 0.003%). This variant has been observed in individual(s) with classic citrullinemia (PMID: 7557970, 11941481, 16475226; Invitae). ClinVar contains an entry for this variant (Variation ID: 265962). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). 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. -

See cases

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Mar 29, 2022

ACMG classification criteria: PS3, PS4, PM2, PM3 -

not provided

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Mar 01, 2023

Published functional studies demonstrate that the variant results in 132 bp deletion in exon 13 (Kobayashi et al., 1995); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 7557970, 32778825, 28111830) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.37

CADD

Benign

5.8

DANN

Benign

0.91

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

1.0

SpliceAI score (max)

0.92

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.92

Position offset: -5

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over