Genetic Variant MGAT2:p.Leu87Leu (chr14-49621527-C-T) – ACMG Classification: Likely_benign (-1 pts)

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP7

The NM_002408.4(MGAT2):c.259C>T(p.Leu87Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,512 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. L87L) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MGAT2
NM_002408.4 synonymous

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 2.46

Publications

0 publications found

Variant links:

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]

MGAT2 Gene-Disease associations (from GenCC):

MGAT2-congenital disorder of glycosylation
Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen, G2P, Orphanet

MGAT2 links:

ENSG00000258377 (HGNC:):

ENSG00000258377 links:

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new If you want to explore the variant's impact on the transcript NM_002408.4, check out the Mutation Effect Viewer. This is especially useful for frameshift variants or if you want to visualize the effect of exon loss / intron retention.

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.41).

BP7

Synonymous conserved (PhyloP=2.46 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002408.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MGAT2	NM_002408.4	MANE Select	c.259C>T	p.Leu87Leu	synonymous	Exon 1 of 1	NP_002399.1	Q10469

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MGAT2	ENST00000305386.4	TSL:6 MANE Select	c.259C>T	p.Leu87Leu	synonymous	Exon 1 of 1	ENSP00000307423.2	Q10469
	ENSG00000258377	ENST00000555043.2	TSL:2	n.1954G>A		non_coding_transcript_exon	Exon 1 of 2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1460512

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726380

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.0000299

AC:

AN:

33460

American (AMR)

AF:

0.00

AC:

AN:

44706

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26128

East Asian (EAS)

AF:

0.00

AC:

AN:

39680

South Asian (SAS)

AF:

0.00

AC:

AN:

86252

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52764

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111432

Other (OTH)

AF:

0.00

AC:

AN:

60326

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.41

CADD

Benign

(source)

DANN

Benign

0.95

PhyloP100

2.5

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over