1-45509016-A-T

Position:

chr1-45509016-A-T

Variant summary

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

The NM_015506.3(MMACHC):c.650A>T(p.Glu217Val) variant causes a missense change. The variant allele was found at a frequency of 0.000129 in 1,614,068 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E217G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

MMACHC
NM_015506.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 5.44

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM1

In a chain Cyanocobalamin reductase / alkylcobalamin dealkylase (size 281) in uniprot entity MMAC_HUMAN there are 49 pathogenic changes around while only 14 benign (78%) in NM_015506.3

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MMACHC	NM_015506.3 linkuse as main transcript	c.650A>T	p.Glu217Val	missense_variant	4/4	ENST00000401061.9	NP_056321.2	Q9Y4U1
MMACHC	NM_001330540.2 linkuse as main transcript	c.479A>T	p.Glu160Val	missense_variant	4/4		NP_001317469.1	Q9Y4U1A0A0C4DGU2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MMACHC	ENST00000401061.9 linkuse as main transcript	c.650A>T	p.Glu217Val	missense_variant	4/4	2	NM_015506.3	ENSP00000383840.4		Q9Y4U1
MMACHC	ENST00000616135.1 linkuse as main transcript	c.479A>T	p.Glu160Val	missense_variant	4/5	2		ENSP00000478859.1		A0A0C4DGU2

Frequencies

GnomAD3 genomes

AF:

0.0000854

AC:

AN:

152190

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:

0.0000941

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000176

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000922

AC:

AN:

249452

Hom.:

AF XY:

0.000103

AC XY:

AN XY:

135334

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:

0.000203

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000133

AC:

195

AN:

1461878

Hom.:

Cov.:

AF XY:

0.000132

AC XY:

AN XY:

727242

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

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:

0.000165

Gnomad4 OTH exome

AF:

0.000166

GnomAD4 genome

AF:

0.0000854

AC:

AN:

152190

Hom.:

Cov.:

AF XY:

0.0000672

AC XY:

AN XY:

74358

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:

0.0000941

Gnomad4 NFE

AF:

0.000176

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000227

Hom.:

Bravo

AF:

0.0000869

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000519

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000479

AC:

ExAC

AF:

0.0000909

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cobalamin C disease

Uncertain:4

Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Jun 20, 2024	- -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Apr 21, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 12, 2021	This sequence change replaces glutamic acid with valine at codon 217 of the MMACHC protein (p.Glu217Val). The glutamic acid residue is moderately conserved and there is a moderate physicochemical difference between glutamic acid and valine. This variant is present in population databases (rs199641732, ExAC 0.02%). This missense change has been observed in individual(s) with MMACHC-related conditions (Invitae). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Apr 11, 2023	- -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 26, 2023

The c.650A>T (p.E217V) alteration is located in exon 4 (coding exon 4) of the MMACHC gene. This alteration results from a A to T substitution at nucleotide position 650, causing the glutamic acid (E) at amino acid position 217 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

May 06, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Uncertain

0.019

BayesDel_noAF

Uncertain

0.060

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.83

D;T

Eigen

Uncertain

0.52

Eigen_PC

Uncertain

0.57

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.86

D;D

M_CAP

Uncertain

0.25

MetaRNN

Uncertain

0.48

T;T

MetaSVM

Pathogenic

0.81

MutationAssessor

Pathogenic

3.1

M;.

PrimateAI

Benign

0.41

PROVEAN

Uncertain

-4.2

D;.

REVEL

Uncertain

0.64

Sift

Uncertain

0.022

D;.

Sift4G

Uncertain

0.026

D;D

Polyphen

0.92

P;.

Vest4

0.38

MVP

0.99

MPC

0.035

ClinPred

0.78

GERP RS

5.8

Varity_R

0.63

gMVP

0.68

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over