rs121908641

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1PM2PP3_ModeratePP5_Very_Strong

The NM_054012.4(ASS1):​c.1168G>A​(p.Gly390Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000316 in 1,613,642 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.00026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00032 ( 0 hom. )

Consequence

ASS1
NM_054012.4 missense

Scores

16
2
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:20O:1

Conservation

PhyloP100: 7.72
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM1
In a helix (size 19) in uniprot entity ASSY_HUMAN there are 6 pathogenic changes around while only 0 benign (100%) in NM_054012.4
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.938
PP5
Variant 9-130499545-G-A is Pathogenic according to our data. Variant chr9-130499545-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 6329.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-130499545-G-A is described in Lovd as [Pathogenic]. Variant chr9-130499545-G-A is described in Lovd as [Pathogenic]. Variant chr9-130499545-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ASS1NM_054012.4 linkc.1168G>A p.Gly390Arg missense_variant Exon 14 of 15 ENST00000352480.10 NP_446464.1 P00966Q5T6L4
ASS1NM_000050.4 linkc.1168G>A p.Gly390Arg missense_variant Exon 15 of 16 NP_000041.2 P00966Q5T6L4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ASS1ENST00000352480.10 linkc.1168G>A p.Gly390Arg missense_variant Exon 14 of 15 1 NM_054012.4 ENSP00000253004.6 P00966
ASS1ENST00000372393.7 linkc.1168G>A p.Gly390Arg missense_variant Exon 15 of 16 5 ENSP00000361469.2 P00966
ASS1ENST00000372394.5 linkc.1168G>A p.Gly390Arg missense_variant Exon 15 of 16 2 ENSP00000361471.1 P00966
ASS1ENST00000372386.6 linkn.439G>A non_coding_transcript_exon_variant Exon 5 of 6 3

Frequencies

GnomAD3 genomes
AF:
0.000263
AC:
40
AN:
152172
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000965
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000621
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000456
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000315
AC:
79
AN:
250658
Hom.:
0
AF XY:
0.000399
AC XY:
54
AN XY:
135460
show subpopulations
Gnomad AFR exome
AF:
0.0000621
Gnomad AMR exome
AF:
0.000232
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00105
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000326
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000322
AC:
470
AN:
1461470
Hom.:
0
Cov.:
31
AF XY:
0.000326
AC XY:
237
AN XY:
726970
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.000952
Gnomad4 FIN exome
AF:
0.0000187
Gnomad4 NFE exome
AF:
0.000322
Gnomad4 OTH exome
AF:
0.000282
GnomAD4 genome
AF:
0.000263
AC:
40
AN:
152172
Hom.:
0
Cov.:
32
AF XY:
0.000296
AC XY:
22
AN XY:
74328
show subpopulations
Gnomad4 AFR
AF:
0.0000965
Gnomad4 AMR
AF:
0.000131
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000621
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000456
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000149
Hom.:
0
Bravo
AF:
0.000257
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.000233
AC:
2
ExAC
AF:
0.000371
AC:
45
EpiCase
AF:
0.000382
EpiControl
AF:
0.000356

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:20Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Citrullinemia type I Pathogenic:15Other:1
Jan 31, 2019
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was classified as: Pathogenic. The following ACMG criteria were applied in classifying this variant: PS1,PS3,PM2,PM3,PP3,PP4. -

Mar 28, 2024
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.Gly390Arg variant in AAS1 has been reported in >30 individuals with citrullinemia type I (both in the homozygous and compound heterozygous state) and segregated with disease in at least 5 affected relatives from 5 families. It is the most common variant identified in patients with the classical phenotype (Vilaseca 2001 PMID: 11708871, Gao 2003 PMID: 12815590, Berning 2008 PMID: 18473344, Engel 2009 PMID: 19006241, Laróvere 2009 PMID: 19358837, Laróvere 2012 PMID: 23430935). This variant has also been reported by other clinical laboratories in ClinVar (Variation ID: 6329) and has been identified in 0.06% (3/4828) of South Asian chromosomes by gnomAD (http://gnomad.broadinstitute.org, v.3.1.2). In vitro functional studies provide some evidence that this variant impacts protein function, demonstrating less than 2% of wild type argininosuccinate synthetase activity (Berning 2008 PMID: 18473344, Shaheen 1994PMID: 8792870) and computational prediction tools and conservation analyses are consistent with pathogenicity. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive citrullinemia type I. ACMG/AMP Criteria applied: PM3_Very Strong, PP1_Moderate, PS3_Supporting, PP3. -

-
Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nov 12, 2019
Myriad Genetics, Inc.
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

NM_000050.4(ASS1):c.1168G>A(G390R) is classified as likely pathogenic in the context of citrullinemia type 1. Sources cited for classification include the following: PMID 18473344, 16475226, 12815590, and 7557970. Classification of NM_000050.4(ASS1):c.1168G>A(G390R) is based on the following criteria: There is strong evidence of association with the variant and the relevant disease and there is functional data showing deficient protein function. Please note: this variant was assessed in the context of healthy population screening. -

Apr 04, 2023
Genomic Medicine Lab, University of California San Francisco
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Sep 09, 2021
Revvity Omics, Revvity
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

-
Neuberg Centre For Genomic Medicine, NCGM
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The c.1168G>A (p.Gly390Arg) missense variant in ASS1 gene has been reported in homozygous state in individuals affected with citrullinemia (Laróvere et al., 2012). Experimental studies have shown that this variant disrupts the function and substantially reduces the activity of the encoded enzyme in vitro (Berning et al., 2008). This variant is reported with the allele frequency (0.03%) in the gnomad and novel in 1000 genome database. This variant has been reported to the ClinVar database as Pathogenic/Likely Pathogenic. The amino acid Gly at position 390 is changed to a Arg changing protein sequence and it might alter its composition and physico-chemical properties. For these reasons, this variant has been classified as Pathogenic. -

Mar 01, 2009
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

May 18, 2017
Fulgent Genetics, Fulgent Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Aug 09, 2023
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: research

- -

-
GeneReviews
Significance: not provided
Review Status: no classification provided
Collection Method: literature only

- -

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

- -

Jul 22, 2021
Genome-Nilou Lab
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mar 27, 2024
Baylor Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Aug 29, 2016
Foundation for Research in Genetics and Endocrinology, FRIGE's Institute of Human Genetics
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

The observed variant c.1168G>A (p.Gly390Arg) is not reported in 1000 Genomes and has a minor allele frequency of 0.00040 in ExAC databases. The in silico prediction of the variant is disease causing by MutationTaster2, damaging by SIFT and probably damaging by Polyphen2. -

Apr 12, 2016
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: The ASS1 c.1168G>A variant affects a conserved nucleotide, resulting in amino acid change from Gly to Arg. Gly390 is located in a-helix 12 and is important for intermolecular contact of the multimerization tails, and 5/5 in-silico tools predict damaging outcome for this variant. The enzymatic ASS activity of G390R was shown to be below 2% of the wild-type protein (Berning_HM_2008). This variant was found in 45/113324 control chromosomes at a frequency of 0.0003971, which does not exceed maximal expected frequency of a pathogenic ASS1 allele (0.0040825). This variant is reported as the most common mutation in patients with the classic phenotype of citrullinemia. In addition, several clinical laboratories classified this variant as pathogenic. Taken together, this variant was classified as pathogenic. -

not provided Pathogenic:3
Dec 01, 2019
CeGaT Center for Human Genetics Tuebingen
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jul 10, 2021
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Published functional studies demonstrate less than 2% of wild type argininosuccinate synthetase activity (Berning et al., 2008); 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: 27535533, 31469252, 31980526, 25433810, 7557970, 11941481, 30848473, 11708871, 8792870, 19006241, 12815590, 23430935, 19358837, 2358466, 28741715, 16421053, 28132756, 27287393, 22975760, 25087612, 18473344, 16475226) -

Apr 20, 2018
Eurofins Ntd Llc (ga)
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Inborn genetic diseases Pathogenic:1
Feb 04, 2022
Ambry Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The c.1168G>A (p.G390R) alteration is located in exon 15 (coding exon 13) of the ASS1 gene. This alteration results from a G to A substitution at nucleotide position 1168, causing the glycine (G) at amino acid position 390 to be replaced by an arginine (R). Based on data from gnomAD, the A allele has an overall frequency of 0.03% (86/282044) total alleles studied. The highest observed frequency was 0.11% (32/30412) of South Asian alleles. This mutation has been reported in the homozygous and compound heterozygous states in patients with citrullinemia and is the most commonly reported mutation in multiple cohorts worldwide (Gao, 2003; Diez-Fernandez, 2017). This amino acid position is highly conserved in available vertebrate species. In vitro studies demonstrate that this mutation results in significantly reduced enzymatic activity in multiple cell types (Berning, 2008; Zielonka, 2019). This alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, this alteration is classified as pathogenic. -

Citrullinemia Pathogenic:1
Jan 08, 2025
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 arginine, which is basic and polar, at codon 390 of the ASS1 protein (p.Gly390Arg). This variant is present in population databases (rs121908641, gnomAD 0.1%). This missense change has been observed in individuals with citrullinemia type I (PMID: 11708871, 12815590, 18473344, 19006241, 19358837, 23430935). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 6329). 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%. Experimental studies have shown that this missense change affects ASS1 function (PMID: 8792870, 18473344). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.97
BayesDel_addAF
Pathogenic
0.29
D
BayesDel_noAF
Pathogenic
0.59
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
1.0
D;D;D
Eigen
Pathogenic
0.85
Eigen_PC
Pathogenic
0.69
FATHMM_MKL
Uncertain
0.97
D
LIST_S2
Uncertain
0.90
.;.;D
M_CAP
Pathogenic
0.67
D
MetaRNN
Pathogenic
0.94
D;D;D
MetaSVM
Pathogenic
0.89
D
MutationAssessor
Pathogenic
3.8
H;H;H
PrimateAI
Pathogenic
0.83
D
PROVEAN
Pathogenic
-7.5
D;D;D
REVEL
Pathogenic
0.97
Sift
Pathogenic
0.0
D;D;D
Sift4G
Pathogenic
0.0
D;D;D
Polyphen
1.0
D;D;D
Vest4
0.98
MutPred
0.99
Gain of MoRF binding (P = 0.0528);Gain of MoRF binding (P = 0.0528);Gain of MoRF binding (P = 0.0528);
MVP
0.99
MPC
0.97
ClinPred
0.90
D
GERP RS
3.6
Varity_R
0.98
gMVP
0.97

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

LitVar

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

Other links and lift over

dbSNP: rs121908641; hg19: chr9-133374932; API