9-33166941-G-A

Position:

chr9-33166941-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001497.4(B4GALT1):c.229C>T(p.Leu77Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000121 in 1,572,234 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

B4GALT1
NM_001497.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.608

Variant links:

Genes affected

B4GALT1 (HGNC:924): (beta-1,4-galactosyltransferase 1) 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 is unique among the beta4GalT genes because it encodes an enzyme that participates both in glycoconjugate and lactose biosynthesis. For the first activity, the enzyme adds galactose to N-acetylglucosamine residues that are either monosaccharides or the nonreducing ends of glycoprotein carbohydrate chains. The second activity is restricted to lactating mammary tissues where the enzyme forms a heterodimer with alpha-lactalbumin to catalyze UDP-galactose + D-glucose <=> UDP + lactose. The two enzymatic forms result from alternate transcription initiation sites and post-translational processing. Two transcripts, which differ only at the 5' end, with approximate lengths of 4.1 kb and 3.9 kb encode the same protein. The longer transcript encodes the type II membrane-bound, trans-Golgi resident protein involved in glycoconjugate biosynthesis. The shorter transcript encodes a protein which is cleaved to form the soluble lactose synthase. [provided by RefSeq, Jul 2008]

B4GALT1 links:

B4GALT1-AS1 (HGNC:):

B4GALT1-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

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 (MetaRNN=0.10614544).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
B4GALT1	NM_001497.4 linkuse as main transcript	c.229C>T	p.Leu77Phe	missense_variant	1/6	ENST00000379731.5	NP_001488.2	P15291-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	UniProt
B4GALT1	ENST00000379731.5 linkuse as main transcript	c.229C>T	p.Leu77Phe	missense_variant	1/6	1	NM_001497.4	ENSP00000369055.4	P15291-1
B4GALT1	ENST00000535206.5 linkuse as main transcript	c.229C>T	p.Leu77Phe	missense_variant	1/3	1		ENSP00000440341.1	Q86XA6
B4GALT1-AS1	ENST00000426270.5 linkuse as main transcript	n.-34G>A		upstream_gene_variant		2
B4GALT1-AS1	ENST00000654325.1 linkuse as main transcript	n.-7G>A		upstream_gene_variant

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152124

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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:

0.000103

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000396

AC:

AN:

176720

Hom.:

AF XY:

0.0000409

AC XY:

AN XY:

97710

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000364

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:

0.0000784

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000127

AC:

180

AN:

1420110

Hom.:

Cov.:

AF XY:

0.000115

AC XY:

AN XY:

704134

show subpopulations

Gnomad4 AFR exome

AF:

0.0000605

Gnomad4 AMR exome

AF:

0.0000773

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000153

Gnomad4 OTH exome

AF:

0.000118

GnomAD4 genome

AF:

0.0000657

AC:

AN:

152124

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74310

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000103

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000362

Hom.:

Bravo

AF:

0.0000642

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000245

AC:

ExAC

AF:

0.0000430

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 21, 2023

The c.229C>T (p.L77F) alteration is located in exon 1 (coding exon 1) of the B4GALT1 gene. This alteration results from a C to T substitution at nucleotide position 229, causing the leucine (L) at amino acid position 77 to be replaced by a phenylalanine (F). 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

Benign

0.075

BayesDel_addAF

Benign

-0.41

BayesDel_noAF

Benign

-0.63

CADD

Benign

DANN

Benign

0.84

DEOGEN2

Benign

0.0066

T;T

Eigen

Benign

-0.41

Eigen_PC

Benign

-0.50

FATHMM_MKL

Benign

0.10

LIST_S2

Benign

0.72

T;T

M_CAP

Benign

0.052

MetaRNN

Benign

0.11

T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.7

.;L

PrimateAI

Uncertain

0.61

PROVEAN

Benign

-0.73

N;N

REVEL

Benign

0.053

Sift

Benign

0.63

T;T

Sift4G

Benign

0.45

T;T

Polyphen

0.84

.;P

Vest4

0.23

MVP

0.71

MPC

0.57

ClinPred

0.071

GERP RS

2.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.0

Varity_R

0.043

gMVP

0.33

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