rs765284825
Variant summary
Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong
The NM_000255.4(MMUT):c.1846C>T(p.Arg616Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000806 in 1,613,862 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/20 in silico tools predict a damaging 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. R616H) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000255.4 missense
Scores
Clinical Significance
Conservation
Publications
- methylmalonic aciduria due to methylmalonyl-CoA mutase deficiencyInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), G2P
- vitamin B12-unresponsive methylmalonic acidemia type mut-Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- vitamin B12-unresponsive methylmalonic acidemia type mut0Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 19 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MMUT | NM_000255.4 | c.1846C>T | p.Arg616Cys | missense_variant | Exon 11 of 13 | ENST00000274813.4 | NP_000246.2 | |
| MMUT | XM_005249143.4 | c.1846C>T | p.Arg616Cys | missense_variant | Exon 11 of 13 | XP_005249200.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152124Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 251264 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.00000821 AC: 12AN: 1461738Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3AN XY: 727184 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152124Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74306 show subpopulations
ClinVar
Submissions by phenotype
Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency Pathogenic:3
This submission and the accompanying classification are no longer maintained by the submitter.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. -
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PS3, PP3, PM2, PM3 -
not provided Pathogenic:1
This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 616 of the MUT protein (p.Arg616Cys). This variant is present in population databases (rs765284825, gnomAD 0.009%). This missense change has been observed in individual(s) with methylmalonic aciduria (PMID: 15781192, 16281286, 20549364, 26790480, 30209273). 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: 551499). 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 expected to disrupt MUT protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects MUT function (PMID: 19955418). For these reasons, this variant has been classified as Pathogenic. -
Methylmalonic aciduria due to complete methylmalonyl-CoA mutase deficiency Pathogenic:1
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Methylmalonic acidemia Pathogenic:1
Variant summary: MUT c.1846C>T (p.Arg616Cys) results in a non-conservative amino acid change located in the Cobalamin (vitamin B12)-binding domain of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.4e-05 in 251264 control chromosomes. c.1846C>T has been reported in the literature in individuals affected with Methylmalonic Acidemia (Martinez_2005, Harrington_2016, Chu_2016). These data indicate that the variant is likely to 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% of normal activity (Merinero_2008). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at