rs1057519360
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3PP5
The NM_005957.5(MTHFR):c.416C>T(p.Thr139Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000173 in 1,614,054 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). Synonymous variant affecting the same amino acid position (i.e. T139T) has been classified as Likely benign.
Frequency
Consequence
NM_005957.5 missense
Scores
Clinical Significance
Conservation
Publications
- homocystinuria due to methylene tetrahydrofolate reductase deficiencyInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152204Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251418 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.0000185 AC: 27AN: 1461850Hom.: 0 Cov.: 31 AF XY: 0.0000234 AC XY: 17AN XY: 727222 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152204Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74340 show subpopulations ⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
ClinVar
Submissions by phenotype
Homocystinuria due to methylene tetrahydrofolate reductase deficiency Pathogenic:2Uncertain:1
Variant summary: MTHFR c.416C>T (p.Thr139Met) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251418 control chromosomes. c.416C>T has been reported in the literature in individuals affected with Homocystinuria Due To Methylene Tetrahydrofolate Reductase Deficiency (Yano_2004, Liu_2024). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in 10%-<30% of normal activity (Yano_2004). The following publications have been ascertained in the context of this evaluation (PMID: 15048559, 37972026). ClinVar contains an entry for this variant (Variation ID: 222893). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
This sequence change replaces threonine with methionine at codon 139 of the MTHFR protein (p.Thr139Met). The threonine residue is moderately conserved and there is a moderate physicochemical difference between threonine and methionine. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individual(s) with severe MTHFR deficiency (PMID: 15048559). ClinVar contains an entry for this variant (Variation ID: 222893). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). Experimental studies have shown that this missense change affects MTHFR function (PMID: 15048559). 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. -
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Schizophrenia;C1856061:Homocystinuria due to methylene tetrahydrofolate reductase deficiency;C1866558:Neural tube defects, folate-sensitive;C3160733:Thrombophilia due to thrombin defect Pathogenic:1
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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