14-49620973-C-T

Position:

• chr14-49620973-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4 BS1_Supporting

The NM_002408.4(MGAT2):​c.-296C>T variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000641 in 702,248 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 0.00018 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000031 (0 hom.)
• Consequence: MGAT2 NM_002408.4 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.736

Genes affected

MGAT2 (HGNC:7045): (alpha-1,6-mannosyl-glycoprotein 2-beta-N-acetylglucosaminyltransferase) The product of this gene is a Golgi enzyme catalyzing an essential step in the conversion of oligomannose to complex N-glycans. The enzyme has the typical glycosyltransferase domains: a short N-terminal cytoplasmic domain, a hydrophobic non-cleavable signal-anchor domain, and a C-terminal catalytic domain. Mutations in this gene may lead to carbohydrate-deficient glycoprotein syndrome, type II. The coding region of this gene is intronless. Transcript variants with a spliced 5' UTR may exist, but their biological validity has not been determined. [provided by RefSeq, Jul 2008]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.18).
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000184 (28/152216) while in subpopulation AFR AF= 0.000675 (28/41468). AF 95% confidence interval is 0.000479. There are 0 homozygotes in gnomad4. There are 9 alleles in male gnomad4 subpopulation. Median coverage is 33. 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	Protein	UniProt
MGAT2	NM_002408.4	c.-296C>T		5_prime_UTR_variant	1/1	ENST00000305386.4	NP_002399.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MGAT2	ENST00000305386.4	c.-296C>T		5_prime_UTR_variant	1/1		NM_002408.4	ENSP00000307423	P1
	ENST00000555043.1	n.2311G>A		non_coding_transcript_exon_variant	2/2	2

Frequencies

GnomAD3 genomes AF: 0.000184 AC: 28 AN: 152216 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.000675

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: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000308 AC: 4 AN: 129786 Hom.: 0 AF XY: 0.0000141 AC XY: 1 AN XY: 70872

Gnomad AFR exome AF: 0.000494

Gnomad AMR exome AF: 0.0000411

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000309 AC: 17 AN: 550032 Hom.: 0 Cov.: 0 AF XY: 0.0000101 AC XY: 3 AN XY: 297782

Gnomad4 AFR exome AF: 0.000760

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: 0.0000301

Gnomad4 NFE exome AF: 0.00000631

Gnomad4 OTH exome AF: 0.0000655

GnomAD4 genome AF: 0.000184 AC: 28 AN: 152216 Hom.: 0 Cov.: 33 AF XY: 0.000121 AC XY: 9 AN XY: 74360

Gnomad4 AFR AF: 0.000675

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: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.000246

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

MGAT2-congenital disorder of glycosylation 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	-0.18
CADD	Benign	8.8
DANN	Benign	0.96
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs754950478; hg19: chr14-50087691;