rs370695114
Variant summary
Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PP2PP3_Moderate
The NM_054012.4(ASS1):c.298C>T(p.Arg100Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000347 in 1,613,126 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R100H) has been classified as Uncertain significance.
Frequency
Consequence
NM_054012.4 missense
Scores
Clinical Significance
Conservation
Publications
- citrullinemia type IInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Myriad Women’s Health, G2P
- acute neonatal citrullinemia type IInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- adult-onset citrullinemia type IInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
Genome browser will be placed here
ACMG classification
Our verdict: Likely_pathogenic. The variant received 7 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000394 AC: 6AN: 152204Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000679 AC: 17AN: 250394 AF XY: 0.0000664 show subpopulations
GnomAD4 exome AF: 0.0000342 AC: 50AN: 1460922Hom.: 0 Cov.: 32 AF XY: 0.0000289 AC XY: 21AN XY: 726754 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000394 AC: 6AN: 152204Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74344 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Citrullinemia type I Uncertain:2
- -
This submission and the accompanying classification are no longer maintained by the submitter.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. -
not specified Uncertain:1
Variant summary: ASS1 c.298C>T (p.Arg100Cys) results in a non-conservative amino acid change located in the Arginosuccinate synthase-like, N-terminal domain (IPR048267) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 6.8e-05 in 250394 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in ASS1 causing Citrullinemia Type I (6.8e-05 vs 0.0041), allowing no conclusion about variant significance. c.298C>T has been reported in the literature along with two pathogenic variants of ASS1 in an individual affected with Citrullinemia Type I. Co-occurrences with other pathogenic variant(s) have been reported (in cis with ASS1, p.Arg157His), providing supporting evidence for a benign role. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 28111830). ClinVar contains an entry for this variant (Variation ID: 553910, VUS). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Citrullinemia Uncertain:1
This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 100 of the ASS1 protein (p.Arg100Cys). This variant is present in population databases (rs370695114, gnomAD 0.02%). This missense change has been observed in individual(s) with citrullinemia (PMID: 28111830; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 553910). 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 not expected to disrupt ASS1 protein function. This variant disrupts the p.Arg100 amino acid residue in ASS1. Other variant(s) that disrupt this residue have been observed in individuals with ASS1-related conditions (PMID: 28111830), which suggests that this may be a clinically significant amino acid residue. 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at