rs745419717

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PP2PP3_Moderate

The NM_015506.3(MMACHC):c.88T>C(p.Trp30Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000366 in 1,614,022 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000037 ( 0 hom. )

Consequence

MMACHC
NM_015506.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 7.48

Publications

1 publications found

Variant links:

Genes affected

MMACHC (HGNC:24525): (metabolism of cobalamin associated C) The exact function of the protein encoded by this gene is not known, however, its C-terminal region shows similarity to TonB, a bacterial protein involved in energy transduction for cobalamin (vitamin B12) uptake. Hence, it is postulated that this protein may have a role in the binding and intracellular trafficking of cobalamin. Mutations in this gene are associated with methylmalonic aciduria and homocystinuria type cblC. [provided by RefSeq, Oct 2009]

MMACHC Gene-Disease associations (from GenCC):

methylmalonic aciduria and homocystinuria type cblC
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Myriad Women’s Health, ClinGen, G2P, Orphanet

MMACHC links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1

In a chain Cyanocobalamin reductase / alkylcobalamin dealkylase (size 281) in uniprot entity MMAC_HUMAN there are 42 pathogenic changes around while only 16 benign (72%) in NM_015506.3

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 28 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: -1.0759 (below the threshold of 3.09). Trascript score misZ: -0.13772 (below the threshold of 3.09). GenCC associations: The gene is linked to methylmalonic aciduria and homocystinuria type cblC.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.934

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MMACHC	NM_015506.3 link	c.88T>C	p.Trp30Arg	missense_variant	Exon 2 of 4	ENST00000401061.9	NP_056321.2	Q9Y4U1
MMACHC	NM_001330540.2 link	c.-84T>C		5_prime_UTR_variant	Exon 2 of 4		NP_001317469.1	Q9Y4U1A0A0C4DGU2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMACHC	ENST00000401061.9 link	c.88T>C	p.Trp30Arg	missense_variant	Exon 2 of 4	2	NM_015506.3	ENSP00000383840.4		Q9Y4U1
MMACHC	ENST00000616135.1 link	c.-84T>C		5_prime_UTR_variant	Exon 2 of 5	2		ENSP00000478859.1		A0A0C4DGU2

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152170

Hom.:

Cov.:

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000120

AC:

AN:

249258

AF XY:

0.0000148

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:

0.0000265

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000369

AC:

AN:

1461852

Hom.:

Cov.:

AF XY:

0.0000303

AC XY:

AN XY:

727224

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86246

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000477

AC:

AN:

1111998

Other (OTH)

AF:

0.0000166

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.490

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000329

AC:

AN:

152170

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74344

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41438

American (AMR)

AF:

0.00

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000735

AC:

AN:

68020

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.505

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.0000868

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.00000827

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cobalamin C disease

Uncertain:4

May 02, 2022

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 06, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces tryptophan, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 30 of the MMACHC protein (p.Trp30Arg). This variant is present in population databases (rs745419717, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with MMACHC-related conditions. ClinVar contains an entry for this variant (Variation ID: 565977). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt MMACHC protein function. 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. -

Apr 07, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Apr 11, 2023

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.83

BayesDel_addAF

Pathogenic

0.49

BayesDel_noAF

Pathogenic

0.49

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.79

Eigen

Pathogenic

0.79

Eigen_PC

Pathogenic

0.75

FATHMM_MKL

Uncertain

0.96

LIST_S2

Benign

0.56

M_CAP

Pathogenic

0.36

MetaRNN

Pathogenic

0.93

MetaSVM

Pathogenic

1.0

MutationAssessor

Uncertain

2.5

PhyloP100

7.5

PrimateAI

Pathogenic

0.80

PROVEAN

Pathogenic

-10

REVEL

Pathogenic

0.94

Sift

Benign

0.081

Sift4G

Uncertain

0.0090

Polyphen

1.0

Vest4

0.94

MutPred

0.73

Gain of methylation at W30 (P = 0.0494);

MVP

0.98

MPC

0.080

ClinPred

1.0

GERP RS

5.4

Varity_R

0.92

gMVP

0.84

Mutation Taster

=41/59

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over