NM_002454.3:c.209G>A

Variant names:

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBS1_SupportingBS2

The NM_002454.3(MTRR):c.209G>A(p.Arg70His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000052 in 1,613,968 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. 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. R70C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000053 ( 2 hom. )

Consequence

MTRR
NM_002454.3 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 2.28

Publications

0 publications found

Variant links:

Genes affected

MTRR (HGNC:7473): (5-methyltetrahydrofolate-homocysteine methyltransferase reductase) This gene encodes a member of the ferredoxin-NADP(+) reductase (FNR) family of electron transferases. This protein functions in the synthesis of methionine by regenerating methionine synthase to a functional state. Because methionine synthesis requires methyl-group transfer by a folate donor, activity of the encoded enzyme is important for folate metabolism and cellular methylation. Mutations in this gene can cause homocystinuria-megaloblastic anemia, cbl E type. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Dec 2015]

MTRR Gene-Disease associations (from GenCC):

methylcobalamin deficiency type cblE
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, G2P, Orphanet

MTRR links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.25252974).

BS1

Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.0000527 (77/1461884) while in subpopulation MID AF = 0.00173 (10/5768). AF 95% confidence interval is 0.00094. There are 2 homozygotes in GnomAdExome4. There are 41 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High Homozygotes in GnomAdExome4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MTRR	NM_002454.3 link	c.209G>A	p.Arg70His	missense_variant	Exon 3 of 15	ENST00000440940.7	NP_002445.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MTRR	ENST00000440940.7 link	c.209G>A	p.Arg70His	missense_variant	Exon 3 of 15	1	NM_002454.3	ENSP00000402510.2

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152084

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000416

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000795

AC:

AN:

251492

AF XY:

0.0000956

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000145

Gnomad ASJ exome

AF:

0.0000992

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000527

AC:

AN:

1461884

Hom.:

Cov.:

AF XY:

0.0000564

AC XY:

AN XY:

727246

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.000112

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.000267

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000297

AC:

AN:

1112002

Other (OTH)

AF:

0.0000828

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.485

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:

0.0000460

AC:

AN:

152084

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74276

show subpopulations

African (AFR)

AF:

0.0000483

AC:

AN:

41422

American (AMR)

AF:

0.00

AC:

AN:

15262

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5180

South Asian (SAS)

AF:

0.000416

AC:

AN:

4808

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10600

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.596

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:

0.0000508

Hom.:

Bravo

AF:

0.0000453

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ExAC

AF:

0.0000494

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Methylcobalamin deficiency type cblE

Uncertain:2

Oct 14, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 70 of the MTRR protein (p.Arg70His). This variant is present in population databases (rs777202031, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with MTRR-related conditions. ClinVar contains an entry for this variant (Variation ID: 466268). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt MTRR protein function with a negative predictive value of 80%. 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. -

Nov 11, 2019

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Disorders of Intracellular Cobalamin Metabolism

Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Inborn genetic diseases

Uncertain:1

Aug 20, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.209G>A (p.R70H) alteration is located in exon 3 (coding exon 2) of the MTRR gene. This alteration results from a G to A substitution at nucleotide position 209, causing the arginine (R) at amino acid position 70 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.094

BayesDel_addAF

Benign

-0.20

BayesDel_noAF

Benign

-0.23

CADD

Benign

(source)

DANN

Pathogenic

1.0

Eigen

Uncertain

0.45

Eigen_PC

Uncertain

0.42

FATHMM_MKL

Uncertain

0.82

LIST_S2

Uncertain

0.89

D;D;D;D

M_CAP

Benign

0.032

MetaRNN

Benign

0.25

T;T;T;T

MetaSVM

Benign

-0.36

MutationAssessor

Benign

1.8

L;.;.;.

PhyloP100

2.3

PrimateAI

Benign

0.32

PROVEAN

Benign

-1.2

N;N;N;N

REVEL

Uncertain

0.37

Sift

Benign

0.55

T;T;T;T

Sift4G

Benign

0.39

T;T;T;T

Vest4

0.34

MutPred

0.51

Loss of phosphorylation at T95 (P = 0.095);.;.;.;

MVP

0.82

MPC

0.067

ClinPred

0.17

GERP RS

3.7

Varity_R

0.086

gMVP

0.52

Mutation Taster

=90/10

polymorphism

(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