rs887126161
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000255.4(MMUT):c.1420C>T(p.Arg474*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000753 in 1,461,044 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000255.4 stop_gained
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 18 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MMUT | ENST00000274813.4 | c.1420C>T | p.Arg474* | stop_gained | Exon 7 of 13 | 1 | NM_000255.4 | ENSP00000274813.3 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000796 AC: 2AN: 251244 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000753 AC: 11AN: 1461044Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4AN XY: 726872 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
not provided Pathogenic:1
This sequence change creates a premature translational stop signal (p.Arg474*) in the MUT gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MUT are known to be pathogenic (PMID: 15781192). This variant is present in population databases (no rsID available, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with methylmalonic aciduria (PMID: 15643616, 16281286). ClinVar contains an entry for this variant (Variation ID: 554873). For these reasons, this variant has been classified as Pathogenic. -
MMUT-related disorder Pathogenic:1
The MMUT c.1420C>T variant is predicted to result in premature protein termination (p.Arg474*). This variant has been reported in the homozygous state or heterozygous state with a second MMUT variant in individuals with methylmalonic acidemia, typically mmut0 type (Acquaviva et al. 2005. PubMed ID: 15643616; Worgan et al. 2006. PubMed ID: 16281286). This variant is reported in 0.0033% of alleles in individuals of South Asian descent in gnomAD. Nonsense variants in MMUT are expected to be pathogenic. This variant is interpreted as pathogenic. -
Methylmalonic aciduria Pathogenic:1
PVS1,PM3(modearte),PM2 -
Methylmalonic aciduria due to complete methylmalonyl-CoA mutase deficiency Pathogenic:1
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Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency Pathogenic: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. -
Methylmalonic acidemia Pathogenic:1
Variant summary: MUT c.1420C>T (p.Arg474X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 8e-06 in 251244 control chromosomes (gnomAD). c.1420C>T has been reported in the literature in multiple homozygous and compound heterozygous individuals affected with Methylmalonic Acidemia (e.g. Acquaviva_2015, Forny_2016, Worgan_2006). These data indicate that the variant is very likely to be associated with disease. Biochemical studies report low incorporation of propionate and low MUT enzyme activity for cells with the variant and assign mut0 class (Forny_2016, Worgan_2006). Two ClinVar submitters (evaluation after 2014) cite the variant as 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