chr1-236795376-T-G

Variant names:

• chr1-236795376-T-G
• rs1057264345
• NM_000254.3:c.-328T>G

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_000254.3(MTR):​c.-328T>G variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000993 in 1,389,672 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000059 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00010 (0 hom.)
• Consequence: MTR NM_000254.3 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -3.54
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• methylcobalamin deficiency type cblG

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

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (REVEL=0.015).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MTR	NM_000254.3	c.-328T>G		5_prime_UTR_variant	Exon 1 of 33	ENST00000366577.10	NP_000245.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MTR	ENST00000366577.10	c.-328T>G		5_prime_UTR_variant	Exon 1 of 33	1	NM_000254.3	ENSP00000355536.5

Frequencies

GnomAD3 genomes AF: 0.0000591 AC: 9 AN: 152232 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000118

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000233 AC: 3 AN: 128482 AF XY: 0.0000285

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000612

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000104 AC: 129 AN: 1237440 Hom.: 0 Cov.: 30 AF XY: 0.000107 AC XY: 65 AN XY: 607204

African (AFR) AF: 0.00 AC: 0 AN: 28020

American (AMR) AF: 0.00 AC: 0 AN: 30816

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 20340

East Asian (EAS) AF: 0.00 AC: 0 AN: 22394

South Asian (SAS) AF: 0.00 AC: 0 AN: 76768

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 19864

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4980

European-Non Finnish (NFE) AF: 0.000124 AC: 122 AN: 985530

Other (OTH) AF: 0.000144 AC: 7 AN: 48728

GnomAD4 genome AF: 0.0000591 AC: 9 AN: 152232 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74366

African (AFR) AF: 0.0000241 AC: 1 AN: 41478

American (AMR) AF: 0.00 AC: 0 AN: 15288

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.000118 AC: 8 AN: 68036

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000302

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Disorders of Intracellular Cobalamin Metabolism Uncertain:1

Jan 12, 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.79
CADD	Benign	4.0
DANN	Benign	0.48
PhyloP100		-3.5
PromoterAI		-0.11	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1057264345; hg19: chr1-236958676;