NM_000255.4:c.2026G>A

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1PM2PP3PP5_Very_Strong

The NM_000255.4(MMUT):c.2026G>A(p.Ala676Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000209 in 1,614,116 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 (★★).

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00022 ( 0 hom. )

Consequence

MMUT
NM_000255.4 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 7.57

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 13 ACMG points.

PM1

In a domain B12-binding (size 132) in uniprot entity MUTA_HUMAN there are 17 pathogenic changes around while only 1 benign (94%) in NM_000255.4

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.839

PP5

Variant 6-49435554-C-T is Pathogenic according to our data. Variant chr6-49435554-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 574601.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr6-49435554-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MMUT	NM_000255.4 link	c.2026G>A	p.Ala676Thr	missense_variant	Exon 12 of 13	ENST00000274813.4	NP_000246.2	P22033A0A024RD82B2R6K1
MMUT	XM_005249143.4 link	c.2026G>A	p.Ala676Thr	missense_variant	Exon 12 of 13		XP_005249200.1	P22033A0A024RD82

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMUT	ENST00000274813.4 link	c.2026G>A	p.Ala676Thr	missense_variant	Exon 12 of 13	1	NM_000255.4	ENSP00000274813.3		P22033

Frequencies

GnomAD3 genomes

AF:

0.000112

AC:

AN:

152208

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000262

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:

0.000191

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000836

AC:

AN:

251166

Hom.:

AF XY:

0.0000958

AC XY:

AN XY:

135762

show subpopulations

Gnomad AFR exome

AF:

0.0000616

Gnomad AMR exome

AF:

0.000203

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000106

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000219

AC:

320

AN:

1461790

Hom.:

Cov.:

AF XY:

0.000226

AC XY:

164

AN XY:

727188

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.000246

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000267

Gnomad4 OTH exome

AF:

0.000149

GnomAD4 genome

AF:

0.000112

AC:

AN:

152326

Hom.:

Cov.:

AF XY:

0.000107

AC XY:

AN XY:

74502

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000261

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000191

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000183

Hom.:

Bravo

AF:

0.000162

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000119

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Jan 23, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 676 of the MUT protein (p.Ala676Thr). This variant is present in population databases (rs147715336, gnomAD 0.02%). This missense change has been observed in individual(s) with methylmalonic acidemia (internal data). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 574601). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt MUT protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Nov 01, 2021

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency

Pathogenic:2

May 04, 2022

Mendelics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jun 30, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

MMUT-related disorder

Pathogenic:1

Dec 02, 2023

PreventionGenetics, part of Exact Sciences

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The MMUT c.2026G>A variant is predicted to result in the amino acid substitution p.Ala676Thr. This variant has been reported in the homozygous and compound heterozygous state in two unrelated individuals with cobalamin deficiency (Brasil et al. 2018. PubMed ID: 30041674). This variant was also described, along with a protein-truncating variant, in an individual who tested positive on newborn screening (Held et al. 2022. PubMed ID: 35225935). This variant is reported in 0.020% of alleles in individuals of Latino descent in gnomAD. This variant is interpreted as likely pathogenic. This variant is interpreted as likely pathogenic. -

Methylmalonic acidemia

Pathogenic:1

Oct 14, 2024

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MMUT c.2026G>A (p.Ala676Thr) results in a non-conservative amino acid change located in the Cobalamin (vitamin B12)-binding domain (IPR006158) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 282576 control chromosomes. c.2026G>A has been reported in the literature in individuals affected with Methylmalonic Acidemia (Brasil_2018, Held_2022, Internal Data). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 30041674, 35225935). ClinVar contains an entry for this variant (Variation ID: 574601). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.88

BayesDel_addAF

Uncertain

0.14

BayesDel_noAF

Pathogenic

0.25

CADD

Uncertain

DANN

Pathogenic

1.0

Eigen

Pathogenic

0.96

Eigen_PC

Pathogenic

0.89

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.34

MetaRNN

Pathogenic

0.84

MetaSVM

Pathogenic

1.1

PrimateAI

Uncertain

0.69

PROVEAN

Uncertain

-3.8

REVEL

Pathogenic

0.88

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0010

Vest4

0.73

MVP

0.99

MPC

0.47

ClinPred

0.98

GERP RS

5.8

gMVP

0.77

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over