chr1-236831958-C-T

Variant names:

• chr1-236831958-C-T
• rs115186224
• NM_000254.3:c.1076-8C>T

Variant summary

Our verdict is Benign. The variant received -18 ACMG points: 0P and 18B. BP4_Moderate BP6_Very_Strong BS1 BS2

The NM_000254.3(MTR):​c.1076-8C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00378 in 1,611,136 control chromosomes in the GnomAD database, including 26 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0031 (2 hom., cov: 33)
  • Exomes 𝑓: 0.0039 (24 hom.)
• Consequence: MTR NM_000254.3 splice_region, intron
• Scores: Splicing: ADA: 0.001340
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:6
• Conservation: PhyloP100: 0.610
• Publications: 1 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: Benign. The variant received -18 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.26).
• BP6: Variant 1-236831958-C-T is Benign according to our data. Variant chr1-236831958-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 296558.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.00311 (474/152302) while in subpopulation NFE AF = 0.00548 (373/68030). AF 95% confidence interval is 0.00502. There are 2 homozygotes in GnomAd4. There are 199 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
• BS2: High Homozygotes in GnomAd4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MTR	NM_000254.3	c.1076-8C>T		splice_region_variant, intron_variant	Intron 12 of 32	ENST00000366577.10	NP_000245.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MTR	ENST00000366577.10	c.1076-8C>T		splice_region_variant, intron_variant	Intron 12 of 32	1	NM_000254.3	ENSP00000355536.5

Frequencies

GnomAD3 genomes AF: 0.00312 AC: 475 AN: 152184 Hom.: 2 Cov.: 33

Gnomad AFR AF: 0.000652

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00354

Gnomad ASJ AF: 0.00144

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.000829

Gnomad FIN AF: 0.000659

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.00548

Gnomad OTH AF: 0.00143

GnomAD2 exomes AF: 0.00259 AC: 651 AN: 251180 AF XY: 0.00243

Gnomad AFR exome AF: 0.000615

Gnomad AMR exome AF: 0.00125

Gnomad ASJ exome AF: 0.000695

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.000924

Gnomad NFE exome AF: 0.00480

Gnomad OTH exome AF: 0.00294

GnomAD4 exome AF: 0.00385 AC: 5619 AN: 1458834 Hom.: 24 Cov.: 30 AF XY: 0.00377 AC XY: 2733 AN XY: 725896

African (AFR) AF: 0.000629 AC: 21 AN: 33408

American (AMR) AF: 0.00136 AC: 61 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00211 AC: 55 AN: 26116

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.000302 AC: 26 AN: 86194

European-Finnish (FIN) AF: 0.00105 AC: 56 AN: 53388

Middle Eastern (MID) AF: 0.00174 AC: 10 AN: 5762

European-Non Finnish (NFE) AF: 0.00471 AC: 5226 AN: 1109276

Other (OTH) AF: 0.00272 AC: 164 AN: 60302

GnomAD4 genome AF: 0.00311 AC: 474 AN: 152302 Hom.: 2 Cov.: 33 AF XY: 0.00267 AC XY: 199 AN XY: 74482

African (AFR) AF: 0.000650 AC: 27 AN: 41552

American (AMR) AF: 0.00353 AC: 54 AN: 15292

Ashkenazi Jewish (ASJ) AF: 0.00144 AC: 5 AN: 3470

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5190

South Asian (SAS) AF: 0.000622 AC: 3 AN: 4820

European-Finnish (FIN) AF: 0.000659 AC: 7 AN: 10630

Middle Eastern (MID) AF: 0.00340 AC: 1 AN: 294

European-Non Finnish (NFE) AF: 0.00548 AC: 373 AN: 68030

Other (OTH) AF: 0.00142 AC: 3 AN: 2116

Alfa AF: 0.00370 Hom.: 2

Bravo AF: 0.00280

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.00545

EpiControl AF: 0.00379

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Benign:3

Mar 01, 2023

CeGaT Center for Human Genetics Tuebingen

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

MTR: BP4, BS2 -

Sep 18, 2023

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Breakthrough Genomics, Breakthrough Genomics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

not specified Benign:1

Feb 28, 2018

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Methylcobalamin deficiency type cblG Benign:1

Jan 06, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Disorders of Intracellular Cobalamin Metabolism Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

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 and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.26
CADD	Benign	14
DANN	Benign	0.86
PhyloP100		0.61
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0013
dbscSNV1_RF	Benign	0.064
SpliceAI score (max)		0.15		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: rs115186224; hg19: chr1-236995258;