dbSNP rs753814352: B4GALT3:p.Arg134Trp (chr1-161175082-G-A) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_003779.4(B4GALT3):c.400C>T(p.Arg134Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,461,758 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

B4GALT3
NM_003779.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.24

Variant links:

Genes affected

B4GALT3 (HGNC:926): (beta-1,4-galactosyltransferase 3) This gene is one of seven beta-1,4-galactosyltransferase (beta4GalT) genes. They encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures. As type II membrane proteins, they have an N-terminal hydrophobic signal sequence that directs the protein to the Golgi apparatus and which then remains uncleaved to function as a transmembrane anchor. By sequence similarity, the beta4GalTs form four groups: beta4GalT1 and beta4GalT2, beta4GalT3 and beta4GalT4, beta4GalT5 and beta4GalT6, and beta4GalT7. This gene encodes an enzyme that may be mainly involved in the synthesis of the first N-acetyllactosamine unit of poly-N-acetyllactosamine chains. Multiple alternatively spliced transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Dec 2010]

B4GALT3 links:

PPOX (HGNC:9280): (protoporphyrinogen oxidase) This gene encodes the penultimate enzyme of heme biosynthesis, which catalyzes the 6-electron oxidation of protoporphyrinogen IX to form protoporphyrin IX. Mutations in this gene cause variegate porphyria, an autosomal dominant disorder of heme metabolism resulting from a deficiency in protoporphyrinogen oxidase, an enzyme located on the inner mitochondrial membrane. Alternatively spliced transcript variants encoding the same protein have been identified. [provided by RefSeq, Jul 2008]

PPOX links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.977

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
B4GALT3	NM_003779.4 link	c.400C>T	p.Arg134Trp	missense_variant	Exon 4 of 8	ENST00000319769.10	NP_003770.1	O60512-1A8K5Z0A0A384NY44

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
B4GALT3	ENST00000319769.10 link	c.400C>T	p.Arg134Trp	missense_variant	Exon 4 of 8	1	NM_003779.4	ENSP00000320965.5		O60512-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251362

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135862

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000139

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000109

AC:

AN:

1461758

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

727158

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.000150

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jul 05, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.400C>T (p.R134W) alteration is located in exon 4 (coding exon 2) of the B4GALT3 gene. This alteration results from a C to T substitution at nucleotide position 400, causing the arginine (R) at amino acid position 134 to be replaced by a tryptophan (W). 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

0.99

BayesDel_addAF

Pathogenic

0.18

BayesDel_noAF

Pathogenic

0.19

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.25

T;T;T

Eigen

Pathogenic

0.72

Eigen_PC

Uncertain

0.59

FATHMM_MKL

Uncertain

0.96

LIST_S2

Pathogenic

0.99

.;D;.

M_CAP

Benign

0.073

MetaRNN

Pathogenic

0.98

D;D;D

MetaSVM

Uncertain

-0.26

MutationAssessor

Pathogenic

4.2

H;H;H

PrimateAI

Uncertain

0.77

PROVEAN

Pathogenic

-7.2

D;.;D

REVEL

Uncertain

0.61

Sift

Pathogenic

0.0

D;.;D

Sift4G

Pathogenic

0.0

D;D;D

Polyphen

1.0

D;D;D

Vest4

0.95

MutPred

0.93

Loss of disorder (P = 0.0191);Loss of disorder (P = 0.0191);Loss of disorder (P = 0.0191);

MVP

0.75

MPC

1.2

ClinPred

1.0

GERP RS

4.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.80

gMVP

0.95

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over