rs118204048

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_015702.3(MMADHC):​c.748C>T​(p.Arg250*) 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

Publications

13 publications found
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]
MMADHC Gene-Disease associations (from GenCC):
  • inborn disorder of cobalamin metabolism and transport
    Inheritance: AR Classification: DEFINITIVE Submitted by: Ambry Genetics, ClinGen
  • methylmalonic aciduria and homocystinuria type cblD
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 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 Pathogenic/Likely_pathogenic. ClinVar VariationId is 767.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
MMADHCNM_015702.3 linkc.748C>T p.Arg250* stop_gained Exon 8 of 8 ENST00000303319.10 NP_056517.1 Q9H3L0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MMADHCENST00000303319.10 linkc.748C>T p.Arg250* stop_gained Exon 8 of 8 1 NM_015702.3 ENSP00000301920.5 Q9H3L0
MMADHCENST00000422782.2 linkc.850C>T p.Arg284* stop_gained Exon 9 of 9 5 ENSP00000408331.2 F8WEC0
MMADHCENST00000428879.5 linkc.748C>T p.Arg250* stop_gained Exon 7 of 7 2 ENSP00000389060.1 Q9H3L0

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
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251264
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:
0.0000116
AC:
17
AN:
1461574
Hom.:
0
Cov.:
31
AF XY:
0.00000963
AC XY:
7
AN XY:
727090
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33468
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26122
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39630
South Asian (SAS)
AF:
0.0000348
AC:
3
AN:
86248
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000108
AC:
12
AN:
1111840
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60374
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.454
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.00000658
AC:
1
AN:
152062
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74272
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41412
American (AMR)
AF:
0.00
AC:
0
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10594
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67992
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.000242
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
Apr 03, 2008
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Oct 11, 2023
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 01, 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.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
Sep 11, 2017
Genetic Services Laboratory, University of Chicago
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

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
PhyloP100
4.0
Vest4
0.36
GERP RS
5.0
Mutation Taster
=3/197
disease causing (ClinVar)

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

Other links and lift over

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