chr9-33167103-A-G

Position:

chr9-33167103-A-G

Variant summary

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

The NM_001497.4(B4GALT1):c.67T>C(p.Cys23Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000623 in 1,604,904 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

B4GALT1
NM_001497.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.40

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 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, 0.944

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
B4GALT1	NM_001497.4 linkuse as main transcript	c.67T>C	p.Cys23Arg	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.67T>C	p.Cys23Arg	missense_variant	1/6	1	NM_001497.4	ENSP00000369055.4	P15291-1
B4GALT1	ENST00000535206.5 linkuse as main transcript	c.67T>C	p.Cys23Arg	missense_variant	1/3	1		ENSP00000440341.1	Q86XA6
B4GALT1-AS1	ENST00000426270.5 linkuse as main transcript	n.72+57A>G		intron_variant		2
B4GALT1-AS1	ENST00000654325.1 linkuse as main transcript	n.99+57A>G		intron_variant

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152238

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000169

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

GnomAD4 exome

AF:

0.00000207

AC:

AN:

1452666

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

722824

show subpopulations

Gnomad4 AFR exome

AF:

0.0000898

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:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152238

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74380

show subpopulations

Gnomad4 AFR

AF:

0.000169

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:

0.0000151

ExAC

AF:

0.00000841

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

Oct 09, 2024

The c.67T>C (p.C23R) alteration is located in exon 1 (coding exon 1) of the B4GALT1 gene. This alteration results from a T to C substitution at nucleotide position 67, causing the cysteine (C) at amino acid position 23 to be replaced by an arginine (R). 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

0.98

BayesDel_addAF

Uncertain

0.16

BayesDel_noAF

Uncertain

-0.010

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.21

T;D

Eigen

Uncertain

0.50

Eigen_PC

Uncertain

0.42

FATHMM_MKL

Benign

0.76

LIST_S2

Benign

0.70

T;T

M_CAP

Pathogenic

0.92

MetaRNN

Pathogenic

0.94

D;D

MetaSVM

Uncertain

-0.26

MutationAssessor

Benign

1.9

.;L

PrimateAI

Pathogenic

0.92

PROVEAN

Pathogenic

-5.7

D;D

REVEL

Uncertain

0.60

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

1.0

.;D

Vest4

0.68

MutPred

0.84

Gain of MoRF binding (P = 0.0065);Gain of MoRF binding (P = 0.0065);

MVP

0.86

MPC

1.8

ClinPred

1.0

GERP RS

3.6

Varity_R

0.95

gMVP

0.89

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