NM_005957.5:c.137G>A
Variant summary
Our verdict is Pathogenic. Variant got 13 ACMG points: 14P and 1B. PM1PM2PM5PP5_Very_StrongBP4
The NM_005957.5(MTHFR):c.137G>A(p.Arg46Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000266 in 1,614,024 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R46W) has been classified as Likely benign.
Frequency
Consequence
NM_005957.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 13 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152188Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000199 AC: 5AN: 251332Hom.: 0 AF XY: 0.0000221 AC XY: 3AN XY: 135844
GnomAD4 exome AF: 0.0000267 AC: 39AN: 1461836Hom.: 1 Cov.: 31 AF XY: 0.0000220 AC XY: 16AN XY: 727208
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152188Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74338
ClinVar
Submissions by phenotype
Homocystinuria due to methylene tetrahydrofolate reductase deficiency Pathogenic:3
This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 46 of the MTHFR protein (p.Arg46Gln). This variant is present in population databases (rs776483190, gnomAD 0.003%). This missense change has been observed in individual(s) with severe MTHFR deficiency (PMID: 25736335, 28241805). 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: 187867). 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) has been performed at Invitae 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 MTHFR protein function. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Variant summary: MTHFR c.137G>A (p.Arg46Gln) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 2e-05 in 251332 control chromosomes (gnomAD). c.137G>A has been reported in the literature in individuals affected with Homocystinuria Due To Methylene Tetrahydrofolate Reductase Deficiency (Burda_2015, Iida_2017, Crass_2020). These data indicate that the variant may be associated with disease. At least two publications report experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity (Burda_2015, Weile_2021). The following publications have been ascertained in the context of this evaluation (PMID: 25736335, 33125268, 28241805, 34845156, 35008593, 34214447). One submitter has cited clinical-significance assessments for this variant to ClinVar after 2014 and has classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
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Neural tube defects, folate-sensitive Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at