Genetic Variant MGAT4B:p.Ile315Thr (chr5-179799603-A-G) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_014275.5(MGAT4B):c.944T>C(p.Ile315Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,564 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

MGAT4B
NM_014275.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.25

Publications

0 publications found

Variant links:

Genes affected

MGAT4B (HGNC:7048): (alpha-1,3-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase B) This gene encodes a key glycosyltransferase that regulates the formation of tri- and multiantennary branching structures in the Golgi apparatus. The encoded protein, in addition to the related isoenzyme A, catalyzes the transfer of N-acetylglucosamine (GlcNAc) from UDP-GlcNAc in a beta-1,4 linkage to the Man-alpha-1,3-Man-beta-1,4-GlcNAc arm of R-Man-alpha-1,6(GlcNAc-beta-1,2-Man-alpha-1,3)Man-beta-1,4-GlcNAc-beta-1,4-GlcNAc-beta-1-Asn. The encoded protein may play a role in regulating the availability of serum glycoproteins, oncogenesis, and differentiation. [provided by RefSeq, Jul 2008]

MGAT4B links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MGAT4B	NM_014275.5 link	c.944T>C	p.Ile315Thr	missense_variant	Exon 9 of 15	ENST00000292591.12	NP_055090.1	Q9UQ53-1
MGAT4B	NM_054013.3 link	c.989T>C	p.Ile330Thr	missense_variant	Exon 8 of 14		NP_463459.1	Q9UQ53-3
MGAT4B	XM_024454349.2 link	c.509T>C	p.Ile170Thr	missense_variant	Exon 9 of 15		XP_024310117.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MGAT4B	ENST00000292591.12 link	c.944T>C	p.Ile315Thr	missense_variant	Exon 9 of 15	1	NM_014275.5	ENSP00000292591.7		Q9UQ53-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251414

AF XY:

0.00000736

show subpopulations

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:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461564

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727098

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53110

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1112000

Other (OTH)

AF:

0.00

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Mar 10, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.989T>C (p.I330T) alteration is located in exon 8 (coding exon 8) of the MGAT4B gene. This alteration results from a T to C substitution at nucleotide position 989, causing the isoleucine (I) at amino acid position 330 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.70

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Uncertain

-0.050

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.33

.;T;.

Eigen

Uncertain

0.56

Eigen_PC

Uncertain

0.48

FATHMM_MKL

Uncertain

0.96

M_CAP

Benign

0.050

MetaRNN

Uncertain

0.71

D;D;D

MetaSVM

Benign

-0.47

MutationAssessor

Uncertain

2.5

.;M;.

PhyloP100

9.3

PrimateAI

Pathogenic

0.88

PROVEAN

Uncertain

-3.6

D;D;D

REVEL

Uncertain

0.34

Sift

Uncertain

0.0020

D;D;D

Sift4G

Uncertain

0.0070

D;D;D

Polyphen

0.98

.;D;.

Vest4

0.93

MutPred

0.68

.;Loss of stability (P = 0.0055);.;

MVP

0.14

MPC

1.5

ClinPred

0.97

GERP RS

3.2

PromoterAI

-0.0062

Neutral

(source)

Varity_R

0.65

gMVP

0.80

Mutation Taster

=63/37

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

Details are displayed if max score is > 0.2

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

Publications

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5-179799603-A-G

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over