rs770944877

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_054012.4(ASS1):​c.349G>A​(p.Gly117Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000267 in 1,612,654 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G117D) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

ASS1
NM_054012.4 missense

Scores

12
6
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 8.61

Publications

9 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 19 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_054012.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr9-130458576-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 813405.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
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, 0.992
PP5
Variant 9-130458575-G-A is Pathogenic according to our data. Variant chr9-130458575-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 556029.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.349G>A p.Gly117Ser missense_variant Exon 4 of 15 ENST00000352480.10 NP_446464.1 P00966Q5T6L4
ASS1NM_000050.4 linkc.349G>A p.Gly117Ser missense_variant Exon 5 of 16 NP_000041.2 P00966Q5T6L4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ASS1ENST00000352480.10 linkc.349G>A p.Gly117Ser missense_variant Exon 4 of 15 1 NM_054012.4 ENSP00000253004.6 P00966

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152226
Hom.:
0
Cov.:
33
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:
0.00
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
GnomAD2 exomes
AF:
0.0000121
AC:
3
AN:
247280
AF XY:
0.0000223
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000270
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000288
AC:
42
AN:
1460428
Hom.:
0
Cov.:
32
AF XY:
0.0000275
AC XY:
20
AN XY:
726450
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33446
American (AMR)
AF:
0.00
AC:
0
AN:
44684
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86156
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52940
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5304
European-Non Finnish (NFE)
AF:
0.0000333
AC:
37
AN:
1111766
Other (OTH)
AF:
0.0000332
AC:
2
AN:
60310
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.460
Heterozygous variant carriers
0
3
6
9
12
15
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:
152226
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74358
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41462
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
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:
0.0000147
AC:
1
AN:
68044
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000360
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

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

Submissions by phenotype

Citrullinemia type I Pathogenic:6
Mar 02, 2021
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 13, 2020
Genetics and Molecular Pathology, SA Pathology
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 24, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 04, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 09, 2018
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Sep 16, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Citrullinemia Pathogenic:2
Nov 02, 2023
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 117 of the ASS1 protein (p.Gly117Ser). This variant is present in population databases (rs770944877, gnomAD 0.003%). This missense change has been observed in individual(s) with citrullinemia type I (PMID: 12815590, 16124451, 27287393). ClinVar contains an entry for this variant (Variation ID: 556029). 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 ASS1 protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects ASS1 function (PMID: 27287393). For these reasons, this variant has been classified as Pathogenic. -

Jul 27, 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.349G>A (p.Gly117Ser) 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 1.2e-05 in 247280 control chromosomes. c.349G>A has been reported in the literature in multiple individuals affected with Citrullinemia Type I, including in homozygotes with neonatal/infantile onset (e.g. Diez-Fernandez_2016). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in a complete loss of normal argininosuccinate synthetase enzyme activity (e.g. Diez-Fernandez_2016). The following publication has been ascertained in the context of this evaluation (PMID: 27287393). Five submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic (n=4) or likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as pathogenic. -

ASS1-related disorder Pathogenic:1
Jul 10, 2024
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The ASS1 c.349G>A variant is predicted to result in the amino acid substitution p.Gly117Ser. This variant has been reported in the homozygous state in several patients with a biochemical diagnosis of citrullinemia (Gao et al. 2003. PubMed ID: 12815590; Wasant et al. 2005. PubMed ID: 16124451; Diez-Fernandez et al. 2016. PubMed ID: 27287393). The p.Gly117Ser change was reported to decrease ASS1 enzyme activity to <2% of wild-type (Diez-Fernandez et al. 2016. PubMed ID: 27287393). This variant is reported in 0.0027% of alleles in individuals of European (Non-Finnish) descent in gnomAD. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.51
D
BayesDel_noAF
Pathogenic
0.56
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
1.0
D;D;D;.;.
Eigen
Pathogenic
0.77
Eigen_PC
Pathogenic
0.67
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.87
.;.;D;D;D
M_CAP
Pathogenic
0.60
D
MetaRNN
Pathogenic
0.99
D;D;D;D;D
MetaSVM
Pathogenic
0.99
D
MutationAssessor
Pathogenic
4.4
H;H;H;.;.
PhyloP100
8.6
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-5.7
D;D;D;D;D
REVEL
Pathogenic
0.97
Sift
Uncertain
0.020
D;D;D;D;D
Sift4G
Uncertain
0.038
D;D;D;D;D
Polyphen
0.89
P;P;P;.;.
Vest4
0.97
MutPred
0.98
Loss of ubiquitination at K112 (P = 0.0992);Loss of ubiquitination at K112 (P = 0.0992);Loss of ubiquitination at K112 (P = 0.0992);Loss of ubiquitination at K112 (P = 0.0992);Loss of ubiquitination at K112 (P = 0.0992);
MVP
0.98
MPC
0.81
ClinPred
0.99
D
GERP RS
5.0
Varity_R
0.84
gMVP
0.93
Mutation Taster
=1/99
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs770944877; hg19: chr9-133333962; COSMIC: COSV61689977; API