NM_000255.4:c.1025C>A

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000255.4(MMUT):c.1025C>A(p.Ser342*) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000205 in 1,460,966 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

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

MMUT
NM_000255.4 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 6.32

Publications

3 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 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 6-49453643-G-T is Pathogenic according to our data. Variant chr6-49453643-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 495777.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.1025C>A	p.Ser342*	stop_gained	Exon 5 of 13	ENST00000274813.4	NP_000246.2
MMUT	XM_005249143.4 link	c.1025C>A	p.Ser342*	stop_gained	Exon 5 of 13		XP_005249200.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMUT	ENST00000274813.4 link	c.1025C>A	p.Ser342*	stop_gained	Exon 5 of 13	1	NM_000255.4	ENSP00000274813.3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251246

AF XY:

0.00000736

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000205

AC:

AN:

1460966

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

726850

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33450

American (AMR)

AF:

0.00

AC:

AN:

44706

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26108

East Asian (EAS)

AF:

0.00

AC:

AN:

39566

South Asian (SAS)

AF:

0.00

AC:

AN:

86204

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53400

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5758

European-Non Finnish (NFE)

AF:

0.0000270

AC:

AN:

1111434

Other (OTH)

AF:

0.00

AC:

AN:

60340

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.457

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

Cov.:

Alfa

AF:

0.00

Hom.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:1

Feb 06, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Ser342*) 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 (rs770466993, gnomAD 0.0009%). This premature translational stop signal has been observed in individuals with MUT-related conditions (PMID: 15643616, 19375370). ClinVar contains an entry for this variant (Variation ID: 495777). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic.

Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency

Pathogenic:1

Feb 03, 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.

Methylmalonic acidemia

Pathogenic:1

Jun 26, 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.1025C>A (p.Ser342X) variant results in a premature termination codon, predicted to cause a truncated or absent MUT protein due to nonsense mediated decay, which are commonly known mechanisms for disease. One truncation downstream of this position has been classified as pathogenic by our laboratory (e.g. c.1399C>T, p.Arg467X). One in silico tool predicts a damaging outcome for this variant. The variant of interest has been found in a large, broad control population, ExAC in 1/121004 control chromosomes at a frequency of 0.0000083, which does not exceed the estimated maximal expected allele frequency of a pathogenic MUT variant (0.0024152). This variant was found in methylmalonic acidemia patients in compound heterozigosity with other pathogenic variants such as MUT c.2080C>T, p.Arg694Trp and c.572C>A, p.Ala191Glu (Acquaviva_HumMut_2005, Nizon_Orph J Rare Dis_2013). Taken together, this variant is classified as pathogenic.

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.56

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.87

FATHMM_MKL

Uncertain

0.92

PhyloP100

6.3

Vest4

0.96

GERP RS

5.6

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over