rs118204048

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_015702.3(MMADHC):​c.748C>T​(p.Arg250Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000112 in 1,613,636 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 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

MMADHC
NM_015702.3 stop_gained

Scores

4
2
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 4.04
Variant links:
Genes affected
MMADHC (HGNC:25221): (metabolism of cobalamin associated D) This gene encodes a mitochondrial protein that is involved in an early step of vitamin B12 metabolism. Vitamin B12 (cobalamin) is essential for normal development and survival in humans. Mutations in this gene cause methylmalonic aciduria and homocystinuria type cblD (MMADHC), a disorder of cobalamin metabolism that is characterized by decreased levels of the coenzymes adenosylcobalamin and methylcobalamin. Pseudogenes have been identified on chromosomes 11 and X.[provided by RefSeq, Nov 2008]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.16 CDS is truncated, and there are 3 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 2-149570117-G-A is Pathogenic according to our data. Variant chr2-149570117-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 767.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
MMADHCNM_015702.3 linkuse as main transcriptc.748C>T p.Arg250Ter stop_gained 8/8 ENST00000303319.10

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
MMADHCENST00000303319.10 linkuse as main transcriptc.748C>T p.Arg250Ter stop_gained 8/81 NM_015702.3 P1
MMADHCENST00000422782.2 linkuse as main transcriptc.850C>T p.Arg284Ter stop_gained 9/95
MMADHCENST00000428879.5 linkuse as main transcriptc.748C>T p.Arg250Ter stop_gained 7/72 P1

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152062
Hom.:
0
Cov.:
33
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251264
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135834
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:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000116
AC:
17
AN:
1461574
Hom.:
0
Cov.:
31
AF XY:
0.00000963
AC XY:
7
AN XY:
727090
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:
0.0000348
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000108
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
152062
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74272
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:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000251
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Methylmalonic aciduria and homocystinuria type cblD Pathogenic:3
Likely pathogenic, criteria provided, single submitterclinical testingBaylor GeneticsOct 11, 2023- -
Pathogenic, no assertion criteria providedliterature onlyOMIMApr 03, 2008- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 02, 2024This sequence change creates a premature translational stop signal (p.Arg250*) in the MMADHC gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 47 amino acid(s) of the MMADHC protein. This variant is present in population databases (rs118204048, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with cobalamin D deficiency (PMID: 18385497, 27252276, 28939051, 29620684). ClinVar contains an entry for this variant (Variation ID: 767). For these reasons, this variant has been classified as Pathogenic. -
not provided Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingGenetic Services Laboratory, University of ChicagoSep 11, 2017- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.56
CADD
Pathogenic
43
DANN
Uncertain
1.0
Eigen
Pathogenic
0.86
Eigen_PC
Pathogenic
0.73
FATHMM_MKL
Uncertain
0.92
D
MutationTaster
Benign
1.0
A;A;A
Vest4
0.36
GERP RS
5.0

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.

Other links and lift over

dbSNP: rs118204048; hg19: chr2-150426631; COSMIC: COSV57573569; API