6-49440204-A-G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP3PP5

The NM_000255.4(MMUT):​c.1956+2T>C variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000044 in 1,613,904 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000048 ( 0 hom. )

Consequence

MMUT
NM_000255.4 splice_donor

Scores

5
1
1
Splicing: ADA: 0.9940
1
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:5U:1

Conservation

PhyloP100: 8.93
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, max_spliceai. No scorers claiming Uncertain. Scorers claiming Benign: dbscSNV1_RF.
PP5
Variant 6-49440204-A-G is Pathogenic according to our data. Variant chr6-49440204-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 550143.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Likely_pathogenic=3, Uncertain_significance=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
MMUTNM_000255.4 linkuse as main transcriptc.1956+2T>C splice_donor_variant ENST00000274813.4
MMUTXM_005249143.4 linkuse as main transcriptc.1956+2T>C splice_donor_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
MMUTENST00000274813.4 linkuse as main transcriptc.1956+2T>C splice_donor_variant 1 NM_000255.4 P1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152162
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:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000835
AC:
21
AN:
251360
Hom.:
0
AF XY:
0.000118
AC XY:
16
AN XY:
135848
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 SAS exome
AF:
0.000686
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000479
AC:
70
AN:
1461742
Hom.:
0
Cov.:
32
AF XY:
0.0000688
AC XY:
50
AN XY:
727180
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.000800
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
8.99e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152162
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74342
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000207
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000988
AC:
12

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:5Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency Pathogenic:3Uncertain:1
Pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsOct 31, 2018- -
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaNov 06, 2018This variant occurs in a canonical splice site (donor) and is therefore predicted to disrupt or distort the normal gene product. It was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018) and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score for this variant, it could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene and cDNA change. No publications were found based on this search. Due to the potential impact of splice donor variants and the lack of clarifying evidence, this variant is classified as a variant of unknown significance but suspicious for pathogenicity for this disease. -
Likely pathogenic, criteria provided, single submitterclinical testingCounsylJan 06, 2017- -
Likely pathogenic, criteria provided, single submitterclinical testingCenter for Genomic Medicine, King Faisal Specialist Hospital and Research CenterApr 04, 2024- -
not provided Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingInvitaeDec 31, 2023This sequence change affects a donor splice site in intron 11 of the MUT gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in MUT are known to be pathogenic (PMID: 15781192). This variant is present in population databases (rs750619189, gnomAD 0.06%). This variant has not been reported in the literature in individuals affected with MUT-related conditions. ClinVar contains an entry for this variant (Variation ID: 550143). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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. -
Methylmalonic aciduria due to complete methylmalonyl-CoA mutase deficiency Pathogenic:1
Likely pathogenic, no assertion criteria providedclinical testingNatera, Inc.Sep 16, 2020- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.37
D
BayesDel_noAF
Pathogenic
0.30
CADD
Pathogenic
32
DANN
Uncertain
1.0
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.99
FATHMM_MKL
Pathogenic
0.99
D
MutationTaster
Benign
1.0
D
GERP RS
5.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
0.99
dbscSNV1_RF
Benign
0.65
SpliceAI score (max)
0.99
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.99
Position offset: 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.

Other links and lift over

dbSNP: rs750619189; hg19: chr6-49407917; API