rs1183369398
Variant summary
Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP2
The NM_000255.4(MMUT):c.2197G>A(p.Val733Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000316 in 1,613,804 control chromosomes in the GnomAD database, with no homozygous occurrence. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
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
Genome browser will be placed here
ACMG classification
Our verdict: Uncertain_significance. The variant received 5 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
MMUT | NM_000255.4 | c.2197G>A | p.Val733Ile | missense_variant | Exon 13 of 13 | ENST00000274813.4 | NP_000246.2 | |
MMUT | XM_005249143.4 | c.2197G>A | p.Val733Ile | missense_variant | Exon 13 of 13 | XP_005249200.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000723 AC: 11AN: 152118Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 251390 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.0000274 AC: 40AN: 1461686Hom.: 0 Cov.: 30 AF XY: 0.0000179 AC XY: 13AN XY: 727150 show subpopulations
GnomAD4 genome AF: 0.0000723 AC: 11AN: 152118Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74290 show subpopulations
ClinVar
Submissions by phenotype
not specified Uncertain:1
Variant summary: MUT (aka. MMUT) c.2197G>A (p.Val733Ile) results in a conservative amino acid change located in the cobalamin (vitamin B12)-binding domain (IPR006158) of 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 2.4e-05 in 251390 control chromosomes (gnomAD). c.2197G>A has been reported in the literature in the heterozygous state in a consanguineous couple who had lost two children in infancy, both with clinical symptoms suggestive of Methylmalonic Acidemia (Paleja_2015). These data do not allow clear conclusions about the significance of the variant. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory has submitted a clinical-significance assessment for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
not provided Uncertain:1
This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 733 of the MUT protein (p.Val733Ile). This variant is present in population databases (no rsID available, gnomAD 0.01%). This missense change has been observed in individual(s) with methylmalonic acidemia (PMID: 26174677). ClinVar contains an entry for this variant (Variation ID: 552549). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The isoleucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -
Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency Uncertain:1
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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at