9-130452247-G-A

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP2PP3

The NM_054012.4(ASS1):c.19G>A(p.Val7Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000297 in 1,614,100 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

ASS1
NM_054012.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:5

Conservation

PhyloP100: 9.05

Publications

2 publications found

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 Gene-Disease associations (from GenCC):

citrullinemia type I
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Myriad Women’s Health, G2P
acute neonatal citrullinemia type I
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
adult-onset citrullinemia type I
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ASS1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 49 curated pathogenic missense variants (we use a threshold of 10). The gene has 4 curated benign missense variants. Gene score misZ: 0.75759 (below the threshold of 3.09). Trascript score misZ: 1.8061 (below the threshold of 3.09). GenCC associations: The gene is linked to citrullinemia type I, adult-onset citrullinemia type I, acute neonatal citrullinemia type I.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.798

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ASS1	NM_054012.4 link	c.19G>A	p.Val7Met	missense_variant	Exon 2 of 15	ENST00000352480.10	NP_446464.1	P00966Q5T6L4
ASS1	NM_000050.4 link	c.19G>A	p.Val7Met	missense_variant	Exon 3 of 16		NP_000041.2	P00966Q5T6L4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ASS1	ENST00000352480.10 link	c.19G>A	p.Val7Met	missense_variant	Exon 2 of 15	1	NM_054012.4	ENSP00000253004.6		P00966

Frequencies

GnomAD3 genomes

AF:

0.0000854

AC:

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000265

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000438

AC:

AN:

251350

AF XY:

0.0000515

show subpopulations

Gnomad AFR exome

AF:

0.000308

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000239

AC:

AN:

1461884

Hom.:

Cov.:

AF XY:

0.0000248

AC XY:

AN XY:

727244

show subpopulations

African (AFR)

AF:

0.000358

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000504

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000153

AC:

AN:

1112008

Other (OTH)

AF:

0.0000497

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.462

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.0000854

AC:

AN:

152216

Hom.:

Cov.:

AF XY:

0.000108

AC XY:

AN XY:

74356

show subpopulations

African (AFR)

AF:

0.000265

AC:

AN:

41462

American (AMR)

AF:

0.00

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68048

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.456

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.000102

Hom.:

Bravo

AF:

0.0000982

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000330

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Citrullinemia type I

Pathogenic:1Uncertain:2

Apr 26, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Nov 26, 2023

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 16, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

not specified

Uncertain:1

May 14, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: ASS1 c.19G>A (p.Val7Met) results in a conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 4.4e-05 in 251350 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in ASS1 causing Citrullinemia Type I (4.4e-05 vs 0.0041), allowing no conclusion about variant significance. c.19G>A has been reported in the literature in individuals (in compound heterozygous state) affected with Citrullinemia (Zielonka_2021, Wang_2019). These data do not allow any conclusion about variant significance. At least one publication reports experimental evidence evaluating an impact on protein function, however, does not allow convincing conclusions about the variant effect (Zielonka_2021). The following publications have been ascertained in the context of this evaluation (PMID: 30612563, 31469252). ClinVar contains an entry for this variant (Variation ID: 582173). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Citrullinemia

Uncertain:1

Aug 22, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 7 of the ASS1 protein (p.Val7Met). This variant is present in population databases (rs149938546, gnomAD 0.03%). This missense change has been observed in individual(s) with citrullinemia type 1 and/or citrullinemia type 2 (PMID: 30612563, 31469252). ClinVar contains an entry for this variant (Variation ID: 582173). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C15"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided

Uncertain:1

Nov 18, 2019

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 31469252, 30612563) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.89

BayesDel_addAF

Pathogenic

0.36

BayesDel_noAF

Pathogenic

0.59

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.87

D;D;D;.;.

Eigen

Uncertain

0.62

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Uncertain

0.90

LIST_S2

Uncertain

0.86

.;.;D;D;D

M_CAP

Pathogenic

0.30

MetaRNN

Pathogenic

0.80

D;D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.8

H;H;H;.;.

PhyloP100

9.0

PrimateAI

Uncertain

0.76

PROVEAN

Uncertain

-2.6

D;D;D;N;N

REVEL

Pathogenic

0.85

Sift

Pathogenic

0.0

D;D;D;T;T

Sift4G

Uncertain

0.049

D;D;D;T;T

Polyphen

0.61

P;P;P;.;.

Vest4

0.87

MVP

0.93

MPC

0.32

ClinPred

0.42

GERP RS

5.0

PromoterAI

0.0058

Neutral

(source)

Varity_R

0.88

gMVP

0.88

Mutation Taster

=3/97

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.080

Details are displayed if max score is > 0.2

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

Publications

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9-130452247-G-A

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over