6-49457801-C-T

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.643G>A​(p.Gly215Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,344 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G215C) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

MMUT
NM_000255.4 missense

Scores

14
2
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4O:1

Conservation

PhyloP100: 7.46

Publications

11 publications found
Variant links:
Genes affected
MMUT (HGNC:7526): (methylmalonyl-CoA mutase) This gene encodes the mitochondrial enzyme methylmalonyl Coenzyme A mutase. In humans, the product of this gene is a vitamin B12-dependent enzyme which catalyzes the isomerization of methylmalonyl-CoA to succinyl-CoA, while in other species this enzyme may have different functions. Mutations in this gene may lead to various types of methylmalonic aciduria. [provided by RefSeq, Jul 2008]
MMUT Gene-Disease associations (from GenCC):
  • methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency
    Inheritance: 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 mut0
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 19 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000255.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr6-49457801-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 418341.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 150 curated pathogenic missense variants (we use a threshold of 10). The gene has 9 curated benign missense variants. Gene score misZ: 0.22855 (below the threshold of 3.09). Trascript score misZ: 1.0842 (below the threshold of 3.09). GenCC associations: The gene is linked to vitamin B12-unresponsive methylmalonic acidemia type mut-, methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency, vitamin B12-unresponsive methylmalonic acidemia type mut0.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.99
PP5
Variant 6-49457801-C-T is Pathogenic according to our data. Variant chr6-49457801-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1888.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MMUTNM_000255.4 linkc.643G>A p.Gly215Ser missense_variant Exon 3 of 13 ENST00000274813.4 NP_000246.2 P22033A0A024RD82B2R6K1
MMUTXM_005249143.4 linkc.643G>A p.Gly215Ser missense_variant Exon 3 of 13 XP_005249200.1 P22033A0A024RD82

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MMUTENST00000274813.4 linkc.643G>A p.Gly215Ser missense_variant Exon 3 of 13 1 NM_000255.4 ENSP00000274813.3 P22033

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461344
Hom.:
0
Cov.:
30
AF XY:
0.00000138
AC XY:
1
AN XY:
727012
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33460
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39678
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86228
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53404
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111580
Other (OTH)
AF:
0.00
AC:
0
AN:
60384
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency Pathogenic:1Other:1
Jun 21, 2022
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

not provided Pathogenic:1
Apr 12, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Gly215 amino acid residue in MUT. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 16281286, 26790480). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. ClinVar contains an entry for this variant (Variation ID: 1888). This missense change has been observed in individual(s) with methylmalonic acidemia (PMID: 15643616, 16281286, 16451139, 24059531, 26615597). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 215 of the MUT protein (p.Gly215Ser). -

Methylmalonic acidemia Pathogenic:1
May 23, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: MMUT c.643G>A (p.Gly215Ser) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant was absent in 251190 control chromosomes. c.643G>A has been observed in multiple homozygous or compound heterozygous individuals affected with Methylmalonic Acidemia (e.g. Nizon_2013, Worgan_2006). These data indicate that the variant is very likely to be associated with disease. A different variant located at the same codon (c.643G>T, p.Gly215Cys) has been classified as pathogenic/likely pathogenic in ClinVar, supporting a critical relevance of this residue to MMUT protein function. The following publications have been ascertained in the context of this evaluation (PMID: 24059531, 16281286). ClinVar contains an entry for this variant (Variation ID: 1888). Based on the evidence outlined above, the variant was classified as pathogenic. -

METHYLMALONIC ACIDURIA, mut(0) TYPE Pathogenic:1
Jan 01, 2006
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.59
D
BayesDel_noAF
Pathogenic
0.60
CADD
Pathogenic
29
DANN
Uncertain
1.0
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.88
D
M_CAP
Pathogenic
0.50
D
MetaRNN
Pathogenic
0.99
D
MetaSVM
Pathogenic
0.99
D
PhyloP100
7.5
PrimateAI
Pathogenic
0.87
D
PROVEAN
Pathogenic
-6.0
D
REVEL
Pathogenic
0.98
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Vest4
0.97
MutPred
0.96
Loss of methylation at K212 (P = 0.0739);
MVP
0.99
MPC
0.48
ClinPred
1.0
D
GERP RS
5.7
gMVP
0.97
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs121918258; hg19: chr6-49425514; API