rs777758903

Variant names:

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.2080C>T(p.Arg694Trp) variant causes a missense change. The variant allele was found at a frequency of 0.000026 in 1,613,998 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R694Q) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000028 ( 0 hom. )

Consequence

MMUT
NM_000255.4 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:10O:1

Conservation

PhyloP100: 5.20

Publications

24 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

MMUT links:

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 domain B12-binding (size 132) in uniprot entity MUTA_HUMAN there are 43 pathogenic changes around while only 2 benign (96%) 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 chr6-49435499-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2202131.Status of the report is criteria_provided_single_submitter, 1 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, 0.986

PP5

Variant 6-49435500-G-A is Pathogenic according to our data. Variant chr6-49435500-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 218996.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
MMUT	NM_000255.4 link	c.2080C>T	p.Arg694Trp	missense_variant	Exon 12 of 13	ENST00000274813.4	NP_000246.2
MMUT	XM_005249143.4 link	c.2080C>T	p.Arg694Trp	missense_variant	Exon 12 of 13		XP_005249200.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMUT	ENST00000274813.4 link	c.2080C>T	p.Arg694Trp	missense_variant	Exon 12 of 13	1	NM_000255.4	ENSP00000274813.3

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.0000199

AC:

AN:

251364

AF XY:

0.0000147

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:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000280

AC:

AN:

1461818

Hom.:

Cov.:

AF XY:

0.0000358

AC XY:

AN XY:

727214

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33478

American (AMR)

AF:

0.0000224

AC:

AN:

44702

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.0000580

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000297

AC:

AN:

1111972

Other (OTH)

AF:

0.0000166

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.452

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74344

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41450

American (AMR)

AF:

0.00

AC:

AN:

15272

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5188

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68040

Other (OTH)

AF:

0.000478

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.00

Hom.:

ExAC

AF:

0.0000165

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency

Pathogenic:5Other:1

Dec 18, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Apr 24, 2017

Counsyl

Significance:Pathogenic

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. -

GeneReviews

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

- -

Apr 01, 2023

Clinical Laboratory Sciences Program (CLSP), King Saud bin Abdulaziz University for Health Sciences (KSAU-HS)

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Pathology and Clinical Laboratory Medicine, King Fahad Medical City

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jun 09, 2020

Revvity Omics, Revvity

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Pathogenic:2

Jan 15, 2025

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Published functional studies demonstrate a damaging defect on enzyme activity and MUT gene product function (PMID: 7912889, 25125334); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 7912889, 26615597, 17113806, 25125334, 17957493, 35361390, 16281286, 15643616, 27591164, 17432548, 31622506, 31998365, 34426522, 32754920, 33413471, 36717752, 34668645, 35314707, 33453710) -

May 02, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 694 of the MUT protein (p.Arg694Trp). This variant is present in population databases (rs777758903, gnomAD 0.006%). This missense change has been observed in individual(s) with methylmalonic aciduria (PMID: 17957493, 27591164). ClinVar contains an entry for this variant (Variation ID: 218996). 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: 7912889, 25125334). For these reasons, this variant has been classified as Pathogenic. -

Methylmalonic aciduria

Pathogenic:1

Oct 04, 2024

Al Jalila Children’s Genomics Center, Al Jalila Childrens Speciality Hospital

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

PS3,PM3 (modertae),PM2,PP3 -

Methylmalonic aciduria due to complete methylmalonyl-CoA mutase deficiency

Pathogenic:1

Oct 01, 2020

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Methylmalonic acidemia

Pathogenic:1

Mar 19, 2017

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: The MUT c.2080C>T (p.Arg694Trp) variant located in the AdoCbl-binding domain (via Imtiaz_2014) involves the alteration of a conserved nucleotide, which 4/4 in silico tools (SNPs&GO not captured due to low reliability index) predict a damaging outcome. The variant of interest was observed in the large, broad control population, ExAC, with the allele frequency of 2/121164 (1/60582), which does not exceed the estimated maximal expected allele frequency of a pathogenic MUT variant for 1/414. Multiple publications have cited the variant in affected homozygous and compound heterozygous individuals. In addition, at-least one database classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.68

BayesDel_addAF

Pathogenic

0.41

BayesDel_noAF

Pathogenic

0.53

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

Eigen

Pathogenic

0.95

Eigen_PC

Pathogenic

0.88

FATHMM_MKL

Uncertain

0.96

LIST_S2

Pathogenic

1.0

M_CAP

Pathogenic

0.35

MetaRNN

Pathogenic

0.99

MetaSVM

Pathogenic

1.1

PhyloP100

5.2

PrimateAI

Uncertain

0.67

PROVEAN

Pathogenic

-5.2

REVEL

Pathogenic

0.92

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0070

Vest4

0.94

MutPred

0.92

Loss of methylation at R694 (P = 0.0768);

MVP

0.98

MPC

0.50

ClinPred

0.99

GERP RS

5.8

gMVP

0.91

Mutation Taster

=37/63

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over