Genetic Variant MTRR:p.Val341Phe (chr5-7885818-G-T) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_002454.3(MTRR):c.1021G>T(p.Val341Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V341I) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MTRR
NM_002454.3 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 2.44

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: Uncertain_significance. The variant received 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.92

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MTRR	NM_002454.3 link	c.1021G>T	p.Val341Phe	missense_variant	Exon 7 of 15	ENST00000440940.7	NP_002445.2	Q9UBK8-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MTRR	ENST00000440940.7 link	c.1021G>T	p.Val341Phe	missense_variant	Exon 7 of 15	1	NM_002454.3	ENSP00000402510.2		Q9UBK8-2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461882

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727240

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1112006

Other (OTH)

AF:

0.00

AC:

AN:

60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

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

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.17

BayesDel_addAF

Pathogenic

0.22

BayesDel_noAF

Uncertain

0.080

CADD

Benign

7.7

(source)

DANN

Benign

0.97

Eigen

Benign

-0.0086

Eigen_PC

Benign

0.010

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Benign

0.80

T;T

M_CAP

Benign

0.023

MetaRNN

Pathogenic

0.92

D;D

MetaSVM

Benign

-0.76

MutationAssessor

Benign

1.1

L;.

PhyloP100

2.4

PrimateAI

Benign

0.41

PROVEAN

Benign

-1.9

N;N

REVEL

Uncertain

0.41

Sift

Benign

0.25

T;T

Sift4G

Benign

0.27

T;T

Vest4

0.76

MutPred

0.68

Loss of ubiquitination at K371 (P = 0.0777);.;

MVP

0.87

MPC

0.35

ClinPred

0.67

GERP RS

4.8

Varity_R

0.38

gMVP

0.73

Mutation Taster

=39/61

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over