rs121913579

chr1-236885202-C-Gchr1-236885202-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Moderate PP5_Moderate

The NM_000254.3(MTR):c.2758C>G(p.His920Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. H920H) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: MTR NM_000254.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 7.22

Genes affected

MTR (HGNC:7468): (5-methyltetrahydrofolate-homocysteine methyltransferase) This gene encodes the 5-methyltetrahydrofolate-homocysteine methyltransferase. This enzyme, also known as cobalamin-dependent methionine synthase, catalyzes the final step in methionine biosynthesis. Mutations in MTR have been identified as the underlying cause of methylcobalamin deficiency complementation group G. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, May 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, MTR
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.938
• PP5: Variant 1-236885202-C-G is Pathogenic according to our data. Variant chr1-236885202-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 14280.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MTR	NM_000254.3	c.2758C>G	p.His920Asp	missense_variant	26/33	ENST00000366577.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MTR	ENST00000366577.10	c.2758C>G	p.His920Asp	missense_variant	26/33	1	NM_000254.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251226 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135810

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: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 6.97e-7 AC: 1 AN: 1435088 Hom.: 0 Cov.: 28 AF XY: 0.00000140 AC XY: 1 AN XY: 715838

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: 9.19e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Methylcobalamin deficiency type cblG Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Invitae	Dec 04, 2023	This sequence change replaces histidine, which is basic and polar, with aspartic acid, which is acidic and polar, at codon 920 of the MTR protein (p.His920Asp). This variant is present in population databases (rs121913579, gnomAD 0.0009%). This missense change has been observed in individual(s) with cobalamin G deficiency and/or methionine synthase deficiency (PMID: 8968737, 34625984; Invitae). ClinVar contains an entry for this variant (Variation ID: 14280). 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 MTR protein function with a positive predictive value of 80%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Pathogenic, no assertion criteria provided	literature only	OMIM	Dec 01, 1996	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
Cadd	Pathogenic	27
Dann	Uncertain	0.99
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D;D
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.94	D;D;D
MetaSVM	Uncertain	0.37	D
MutationTaster	Benign	1.0	A;A
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-7.8	D;D;D
REVEL	Pathogenic	0.74
Sift	Uncertain	0.0030	D;D;D
Sift4G	Uncertain	0.0050	D;D;D
Polyphen		1.0	.;D;.
Vest4		0.66
MutPred		0.77		.;Gain of relative solvent accessibility (P = 0.0479);.;
MVP		0.94
MPC		1.5
ClinPred		1.0	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.87
gMVP		0.90

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

Other links and lift over

dbSNP: rs121913579; hg19: chr1-237048502;