1-236795608-C-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_000254.3(MTR):c.-96C>A variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000421 in 1,602,192 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 0.00032 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00043 (0 hom.)
• Consequence: MTR NM_000254.3 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.15

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_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.77).
• BS1: Variant frequency is greater than expected in population nfe. gnomad4_exome allele frequency = 0.000432 (626/1449962) while in subpopulation NFE AF= 0.000547 (607/1109552). AF 95% confidence interval is 0.000511. There are 0 homozygotes in gnomad4_exome. There are 286 alleles in male gnomad4_exome subpopulation. Median coverage is 31. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MTR	NM_000254.3	c.-96C>A		5_prime_UTR_variant	1/33	ENST00000366577.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MTR	ENST00000366577.10	c.-96C>A		5_prime_UTR_variant	1/33	1	NM_000254.3	P1

Frequencies

GnomAD3 genomes AF: 0.000315 AC: 48 AN: 152230 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.000145

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: 0.000617

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000185 AC: 43 AN: 231812 Hom.: 0 AF XY: 0.000196 AC XY: 25 AN XY: 127430

Gnomad AFR exome AF: 0.000142

Gnomad AMR exome AF: 0.0000297

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000600

Gnomad NFE exome AF: 0.000373

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000432 AC: 626 AN: 1449962 Hom.: 0 Cov.: 31 AF XY: 0.000396 AC XY: 286 AN XY: 721488

Gnomad4 AFR exome AF: 0.0000901

Gnomad4 AMR exome AF: 0.0000453

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000432

Gnomad4 NFE exome AF: 0.000547

Gnomad4 OTH exome AF: 0.000200

GnomAD4 genome AF: 0.000315 AC: 48 AN: 152230 Hom.: 0 Cov.: 33 AF XY: 0.000309 AC XY: 23 AN XY: 74378

Gnomad4 AFR AF: 0.000145

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000617

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000171 Hom.: 0

Bravo AF: 0.000253

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Disorders of Intracellular Cobalamin Metabolism Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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	-0.77
Cadd	Benign	2.2
Dann	Benign	0.58
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2

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: rs762741049; hg19: chr1-236958908;