rs121918248

Variant summary

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

The NM_000255.4(MMUT):​c.52C>T​(p.Gln18*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,374 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 (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

MMUT
NM_000255.4 stop_gained

Scores

1
2
4

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5O:1

Conservation

PhyloP100: 0.0290

Publications

7 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 18 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 350 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 6-49459415-G-A is Pathogenic according to our data. Variant chr6-49459415-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 1877.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.52C>T p.Gln18* stop_gained Exon 2 of 13 ENST00000274813.4 NP_000246.2 P22033A0A024RD82B2R6K1
MMUTXM_005249143.4 linkc.52C>T p.Gln18* stop_gained Exon 2 of 13 XP_005249200.1 P22033A0A024RD82

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MMUTENST00000274813.4 linkc.52C>T p.Gln18* stop_gained Exon 2 of 13 1 NM_000255.4 ENSP00000274813.3 P22033

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152100
Hom.:
0
Cov.:
32
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.0000116
AC:
17
AN:
1461274
Hom.:
0
Cov.:
31
AF XY:
0.0000138
AC XY:
10
AN XY:
726948
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33418
American (AMR)
AF:
0.00
AC:
0
AN:
44628
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26094
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86186
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53320
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5692
European-Non Finnish (NFE)
AF:
0.0000153
AC:
17
AN:
1111880
Other (OTH)
AF:
0.00
AC:
0
AN:
60356
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.443
Heterozygous variant carriers
0
2
3
5
6
8
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152100
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74292
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41398
American (AMR)
AF:
0.00
AC:
0
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000228
Hom.:
0
Bravo
AF:
0.0000264
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:5Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency Pathogenic:1Other:1
-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

mut(0) enzymatic subtype when homozygous -

Jul 14, 2017
Counsyl
Significance:Likely 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. -

not provided Pathogenic:1
Oct 17, 2023
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.Gln18*) 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 (rs121918248, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with methylmalonic aciduria (PMID: 1970180, 16281286). ClinVar contains an entry for this variant (Variation ID: 1877). 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 complete methylmalonyl-CoA mutase deficiency Pathogenic:1
Oct 27, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Methylmalonic acidemia Pathogenic:1
Jul 19, 2021
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: MUT c.52C>T (p.Gln18X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 250874 control chromosomes. c.52C>T has been reported in the literature in individuals affected with Methylmalonic Acidemia (Ghosh_2017, Worgan_2006). Cell lines with the variant were reported to have no detectable enzymatic activity (Ledley_1990). Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

METHYLMALONIC ACIDURIA, mut(0) TYPE Pathogenic:1
Mar 01, 1987
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Uncertain
0.060
CADD
Pathogenic
35
DANN
Uncertain
1.0
Eigen
Benign
0.050
Eigen_PC
Benign
-0.21
FATHMM_MKL
Benign
0.11
N
PhyloP100
0.029
Vest4
0.42
GERP RS
1.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.6
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.19
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: rs121918248; hg19: chr6-49427128; API