1-236897020-G-T

Position:

• chr1-236897020-G-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000254.3(MTR):​c.3613G>T​(p.Glu1205*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,560 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 Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MTR NM_000254.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 9.55

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]

MTR (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-236897020-G-T is Pathogenic according to our data. Variant chr1-236897020-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 14287.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MTR	NM_000254.3	c.3613G>T	p.Glu1205*	stop_gained	32/33	ENST00000366577.10	NP_000245.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MTR	ENST00000366577.10	c.3613G>T	p.Glu1205*	stop_gained	32/33	1	NM_000254.3	ENSP00000355536.5
MTR	ENST00000366576.3	c.2275G>T	p.Glu759*	stop_gained	19/20	1		ENSP00000355535.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461560 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727116

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Methylcobalamin deficiency type cblG Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Jul 01, 2002	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Mar 24, 2021	For these reasons, this variant has been classified as Pathogenic. This variant has been observed in individual(s) with methylcobalamin G deficiency (PMID: 12068375). ClinVar contains an entry for this variant (Variation ID: 14287). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Glu1205*) in the MTR gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MTR are known to be pathogenic (PMID: 9683607, 12068375). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	48
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.99	D
Vest4		0.88
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.49		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.49		Position offset: -14

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs121913581; hg19: chr1-237060320;