Variant 2-149570057-A-G details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1PM2

The NM_015702.3(MMADHC):c.808T>C(p.Trp270Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,478 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

MMADHC
NM_015702.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.81

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 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM1

In a mutagenesis_site Decreases methylcobalamin levels. (size 0) in uniprot entity MMAD_HUMAN

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MMADHC	NM_015702.3 linkuse as main transcript	c.808T>C	p.Trp270Arg	missense_variant	8/8	ENST00000303319.10	NP_056517.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris
MMADHC	ENST00000303319.10 linkuse as main transcript	c.808T>C	p.Trp270Arg	missense_variant	8/8	1	NM_015702.3	ENSP00000301920	P1
MMADHC	ENST00000422782.2 linkuse as main transcript	c.910T>C	p.Trp304Arg	missense_variant	9/9	5		ENSP00000408331
MMADHC	ENST00000428879.5 linkuse as main transcript	c.808T>C	p.Trp270Arg	missense_variant	7/7	2		ENSP00000389060	P1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461478

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727042

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000662

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Methylmalonic aciduria and homocystinuria type cblD

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 24, 2021

This sequence change replaces tryptophan with arginine at codon 270 of the MMADHC protein (p.Trp270Arg). The tryptophan residue is highly conserved and there is a moderate physicochemical difference between tryptophan and arginine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with MMADHC-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.24

BayesDel_noAF

Uncertain

0.11

CADD

Uncertain

DANN

Uncertain

0.98

DEOGEN2

Uncertain

0.77

D;D;D

Eigen

Uncertain

0.37

Eigen_PC

Uncertain

0.41

FATHMM_MKL

Uncertain

0.90

LIST_S2

Benign

0.81

.;T;T

M_CAP

Benign

0.076

MetaRNN

Uncertain

0.60

D;D;D

MetaSVM

Uncertain

0.24

MutationAssessor

Uncertain

2.3

M;M;.

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Pathogenic

0.81

PROVEAN

Pathogenic

-10

D;D;D

REVEL

Pathogenic

0.71

Sift

Benign

0.22

T;T;T

Sift4G

Benign

0.33

T;T;T

Polyphen

0.96

D;D;P

Vest4

0.31

MutPred

0.77

.;.;Gain of methylation at W304 (P = 0.0228);

MVP

0.86

MPC

0.14

ClinPred

1.0

GERP RS

5.0

Varity_R

0.89

gMVP

0.81

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

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over