rs746274670

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.277C>T​(p.Arg93Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000533 in 1,614,064 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/20 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. R93H) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000055 ( 0 hom. )

Consequence

MMUT
NM_000255.4 missense

Scores

15
1

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:3U:2

Conservation

PhyloP100: 3.95

Publications

2 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 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 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 chr6-49459189-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 1880.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, 0.966
PP5
Variant 6-49459190-G-A is Pathogenic according to our data. Variant chr6-49459190-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 553695.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.277C>T p.Arg93Cys missense_variant Exon 2 of 13 ENST00000274813.4 NP_000246.2
MMUTXM_005249143.4 linkc.277C>T p.Arg93Cys missense_variant Exon 2 of 13 XP_005249200.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MMUTENST00000274813.4 linkc.277C>T p.Arg93Cys missense_variant Exon 2 of 13 1 NM_000255.4 ENSP00000274813.3

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152180
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000188
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000358
AC:
9
AN:
251452
AF XY:
0.0000441
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.0000615
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000547
AC:
80
AN:
1461884
Hom.:
0
Cov.:
31
AF XY:
0.0000564
AC XY:
41
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.0000749
AC:
4
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000638
AC:
71
AN:
1112004
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.470
Heterozygous variant carriers
0
5
10
14
19
24
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152180
Hom.:
0
Cov.:
32
AF XY:
0.0000673
AC XY:
5
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41446
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.000188
AC:
2
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.558
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000860
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.0000659
AC:
8
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:3Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
May 20, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 93 of the MUT protein (p.Arg93Cys). This variant is present in population databases (rs746274670, gnomAD 0.007%). This missense change has been observed in individual(s) with methylmalonic aciduria (PMID: 26270765, 36717752). ClinVar contains an entry for this variant (Variation ID: 553695). 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%. This variant disrupts the p.Arg93 amino acid residue in MUT. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 1670635, 16281286, 16490061). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic.

Nov 01, 2021
CeGaT Center for Human Genetics Tuebingen
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency Uncertain:2
Sep 12, 2017
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

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.

Myelin Disorders Clinic-Children's Medical Center/Medical Genetics Lab-Tarbiat Modares University, Children's Medical Center, Pediatrics Center of Excellence,
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

Likely inborn error of metabolism Pathogenic:1
Oct 21, 2025
NHS Central & South Genomic Laboratory Hub
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.75
BayesDel_addAF
Pathogenic
0.44
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
33
DANN
Pathogenic
1.0
Eigen
Pathogenic
0.99
Eigen_PC
Pathogenic
0.87
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Pathogenic
1.0
D
M_CAP
Pathogenic
0.34
D
MetaRNN
Pathogenic
0.97
D
MetaSVM
Pathogenic
1.0
D
PhyloP100
4.0
PrimateAI
Pathogenic
0.82
D
PROVEAN
Pathogenic
-7.9
D
REVEL
Pathogenic
0.92
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Vest4
0.97
ClinPred
1.0
D
GERP RS
4.7
gMVP
0.97
Mutation Taster
=48/52
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
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: rs746274670; hg19: chr6-49426903; COSMIC: COSV99222658; COSMIC: COSV99222658; API