rs200019422

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1PM2PP3_StrongPP5_Very_Strong

The NM_000255.4(MMUT):​c.1560+1G>T variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000458 in 1,528,846 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000067 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000044 ( 0 hom. )

Consequence

MMUT
NM_000255.4 splice_donor

Scores

5
1
1
Splicing: ADA: 1.000
2

Clinical Significance

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

Conservation

PhyloP100: 7.50
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 22 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, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant 6-49447669-C-A is Pathogenic according to our data. Variant chr6-49447669-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 203849.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
MMUTNM_000255.4 linkuse as main transcriptc.1560+1G>T splice_donor_variant ENST00000274813.4
MMUTXM_005249143.4 linkuse as main transcriptc.1560+1G>T splice_donor_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
MMUTENST00000274813.4 linkuse as main transcriptc.1560+1G>T splice_donor_variant 1 NM_000255.4 P1

Frequencies

GnomAD3 genomes
AF:
0.00000666
AC:
1
AN:
150238
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:
0.0000148
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000435
AC:
6
AN:
1378608
Hom.:
0
Cov.:
27
AF XY:
0.00000290
AC XY:
2
AN XY:
689504
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.000103
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000193
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000666
AC:
1
AN:
150238
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
73282
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:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000148
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000378
EpiCase
AF:
0.0000546
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpMay 13, 2020Donor and acceptor splice site variants typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in MUT are known to be pathogenic (PMID: 15781192). For these reasons, this variant has been classified as Pathogenic. This variant has been observed in combination with another MUT variant in several individuals affected with methylmalonic aciduria (PMID: 15643616, 17075691). This variant is not present in population databases (ExAC no frequency). This sequence change affects a donor splice site in intron 8 of the MUT gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -
Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingCounsylSep 06, 2017- -
Methylmalonic acidemia Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpJun 13, 2019Variant summary: MUT c.1560+1G>T is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. 5/5 computational tools predict the variant abolishes a 5 prime splicing donor site and a significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 247968 control chromosomes (gnomAD). The variant, c.1560+1G>T, has been reported in the literature in multiple individuals affected with Methylmalonic Acidemia (Cavicchi_2005, Acquaviva_2005, Sakamoto_2007). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One ClinVar submission from other clinical diagnostic laboratories (evaluation after 2014) cites the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.32
CADD
Pathogenic
32
DANN
Uncertain
0.99
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.88
FATHMM_MKL
Pathogenic
0.98
D
MutationTaster
Benign
1.0
D
GERP RS
5.2

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.92
SpliceAI score (max)
1.0
Details are displayed if max score is > 0.2
DS_DL_spliceai
1.0
Position offset: 1

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: rs200019422; hg19: chr6-49415382; API