rs121908636

Variant summary

Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PM2PP2PP3_StrongPP5_Very_Strong

The NM_054012.4(ASS1):​c.40G>A​(p.Gly14Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000161 in 1,614,062 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. G14G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

ASS1
NM_054012.4 missense

Scores

13
3
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 9.05

Publications

8 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 15 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
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, 0.99
PP5
Variant 9-130452268-G-A is Pathogenic according to our data. Variant chr9-130452268-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 6324.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
ASS1NM_054012.4 linkc.40G>A p.Gly14Ser missense_variant Exon 2 of 15 ENST00000352480.10 NP_446464.1
ASS1NM_000050.4 linkc.40G>A p.Gly14Ser missense_variant Exon 3 of 16 NP_000041.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ASS1ENST00000352480.10 linkc.40G>A p.Gly14Ser missense_variant Exon 2 of 15 1 NM_054012.4 ENSP00000253004.6

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152178
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000279
AC:
7
AN:
251146
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000116
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000171
AC:
25
AN:
1461884
Hom.:
0
Cov.:
32
AF XY:
0.0000193
AC XY:
14
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000180
AC:
20
AN:
1112004
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
2
3
5
6
8
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152178
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41446
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000508
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.0000412
AC:
5
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Citrullinemia type I Pathogenic:6
Feb 08, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Aug 07, 2018
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Jul 25, 2023
3billion
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.003%). Predicted Consequence/Location: Missense variant In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.97; 3Cnet: 0.49). Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000006324 /PMID: 2358466). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline.

Jun 01, 2021
Natera, Inc.
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

Apr 04, 2013
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

Aug 06, 2021
New York Genome Center
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Citrullinemia Pathogenic:2
Apr 18, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: ASS1 c.40G>A (p.Gly14Ser) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 251146 control chromosomes (gnomAD). c.40G>A has been reported in the literature in multiple individuals affected with Citrullinemia Type I (Kobayashi_1990, Haberle_2003, Lee_2013, Diez-Fernandez_2016, Diez-Fernandez_2017). These data indicate that the variant is very likely to be associated with disease. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic.

Oct 31, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 14 of the ASS1 protein (p.Gly14Ser). This variant is present in population databases (rs121908636, gnomAD 0.01%). This missense change has been observed in individual(s) with citrullinemia type I (PMID: 2358466, 14680976, 23246278, 27287393, 28111830). ClinVar contains an entry for this variant (Variation ID: 6324). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt ASS1 protein function with a positive predictive value of 80%. For these reasons, this variant has been classified as Pathogenic.

not provided Pathogenic:1
Aug 30, 2024
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 34426522, 2358466, 14680976, 28111830, 23246278, 19006241, 27287393)

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.97
BayesDel_addAF
Pathogenic
0.40
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
1.0
D;D;D;.;.
Eigen
Pathogenic
0.83
Eigen_PC
Pathogenic
0.77
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Benign
0.0
.;.;T;T;T
M_CAP
Pathogenic
0.49
D
MetaRNN
Pathogenic
0.99
D;D;D;D;D
MetaSVM
Pathogenic
0.93
D
MutationAssessor
Pathogenic
4.0
H;H;H;.;.
PhyloP100
9.0
PrimateAI
Pathogenic
0.83
D
PROVEAN
Pathogenic
-5.7
D;D;D;D;D
REVEL
Pathogenic
0.97
Sift
Benign
0.050
D;D;D;T;D
Sift4G
Uncertain
0.0020
D;D;D;D;D
Vest4
0.99
ClinPred
0.98
D
GERP RS
5.0
PromoterAI
-0.047
Neutral
Varity_R
0.92
gMVP
0.97
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs121908636; hg19: chr9-133327655; COSMIC: COSV61689403; API