rs376757912
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PP2PP3_ModeratePP5
The NM_000429.3(MAT1A):c.529C>T(p.Arg177Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,614,082 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R177P) has been classified as Uncertain significance.
Frequency
Consequence
NM_000429.3 missense
Scores
Clinical Significance
Conservation
Publications
- methionine adenosyltransferase deficiencyInheritance: AD, AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics, G2P, Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000394 AC: 6AN: 152130Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000756 AC: 19AN: 251364 AF XY: 0.000103 show subpopulations
GnomAD4 exome AF: 0.0000274 AC: 40AN: 1461834Hom.: 0 Cov.: 30 AF XY: 0.0000371 AC XY: 27AN XY: 727214 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000394 AC: 6AN: 152248Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3AN XY: 74434 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Hepatic methionine adenosyltransferase deficiency Pathogenic:2Uncertain:1
Variant summary: MAT1A c.529C>T (p.Arg177Trp) results in a non-conservative amino acid change located in the S-adenosylmethionine synthetase, central domain (IPR022629) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant allele was found at a frequency of 7.6e-05 in 251364 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in MAT1A causing Hepatic methionine adenosyltransferase deficiency, allowing no conclusion about variant significance. c.529C>T has been observed in multiple individuals affected with Hepatic methionine adenosyltransferase deficiency including as a homozygous, compound heterozygous, or unreported genotype (e.g. Chien_2015, Chadwick_2014, Sen_2019, Sun_2017, Zhao_2022, Internal data). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. ClinVar contains an entry for this variant (Variation ID: 426944). Based on the evidence outlined above, the variant was classified as pathogenic. -
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This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 177 of the MAT1A protein (p.Arg177Trp). This variant is present in population databases (rs376757912, gnomAD 0.04%). This missense change has been observed in individual(s) with autosomal recessive hypermethioninemia (PMID: 24445979, 26289392, 28186605, 31061746; internal data). 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: 426944). 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) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MAT1A protein function. For these reasons, this variant has been classified as Pathogenic. -
MAT1A-related disorder Pathogenic:1
The MAT1A c.529C>T variant is predicted to result in the amino acid substitution p.Arg177Trp. This variant has been reported in the homozygous or compound heterozygous state in individuals with hypermethioninemia (Chien et al 2015. PubMed ID: 26289392; Sun et al 2017. PubMed ID: 28186605; Zhao et al. 2022. PubMed ID: 35760084). It has also been reported in patients with abnormal newborn screen results (Chadwick et al 2014. PubMed ID: 24445979; Sen et al. 2019. PubMed ID: 31061746; Zhang et al. 2020. PubMed ID: 31851615). This variant is reported in 0.039% of alleles in individuals of South Asian descent in gnomAD (http://gnomad.broadinstitute.org/variant/10-82039949-G-A). This variant is interpreted as pathogenic. -
not provided Pathogenic:1
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: 26933843, 26289392, 24445979, 35760084, 31061746, 38380423, 28186605) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at