9-33113742-G-C

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_Strong BP6_Moderate BS1 BS2

The NM_001497.4(B4GALT1):c.1064+32C>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00222 in 1,612,776 control chromosomes in the GnomAD database, including 53 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.011 (32 hom., cov: 33)
  • Exomes 𝑓: 0.0013 (21 hom.)
• Consequence: B4GALT1 NM_001497.4 intron
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.391

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]

ACMG classification

Verdict is Benign. Variant got -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BP6: Variant 9-33113742-G-C is Benign according to our data. Variant chr9-33113742-G-C is described in ClinVar as [Likely_benign]. Clinvar id is 1326535.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.0107 (1628/152214) while in subpopulation AFR AF= 0.0362 (1501/41500). AF 95% confidence interval is 0.0346. There are 32 homozygotes in gnomad4. There are 788 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd at 32 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
B4GALT1	NM_001497.4	c.1064+32C>G		intron_variant		ENST00000379731.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
B4GALT1	ENST00000379731.5	c.1064+32C>G		intron_variant		1	NM_001497.4	P1
B4GALT1	ENST00000535206.5	c.649-8961C>G		intron_variant		1

Frequencies

GnomAD3 genomes AF: 0.0107 AC: 1629 AN: 152096 Hom.: 32 Cov.: 33

Gnomad AFR AF: 0.0363

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00465

Gnomad ASJ AF: 0.00634

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000279

Gnomad OTH AF: 0.00670

GnomAD3 exomes AF: 0.00323 AC: 811 AN: 251396 Hom.: 12 AF XY: 0.00255 AC XY: 347 AN XY: 135872

Gnomad AFR exome AF: 0.0384

Gnomad AMR exome AF: 0.00211

Gnomad ASJ exome AF: 0.00566

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000405

Gnomad OTH exome AF: 0.00179

GnomAD4 exome AF: 0.00134 AC: 1957 AN: 1460562 Hom.: 21 Cov.: 31 AF XY: 0.00122 AC XY: 888 AN XY: 726660

Gnomad4 AFR exome AF: 0.0359

Gnomad4 AMR exome AF: 0.00275

Gnomad4 ASJ exome AF: 0.00647

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000696

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000175

Gnomad4 OTH exome AF: 0.00381

GnomAD4 genome AF: 0.0107 AC: 1628 AN: 152214 Hom.: 32 Cov.: 33 AF XY: 0.0106 AC XY: 788 AN XY: 74428

Gnomad4 AFR AF: 0.0362

Gnomad4 AMR AF: 0.00464

Gnomad4 ASJ AF: 0.00634

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000279

Gnomad4 OTH AF: 0.00664

Alfa AF: 0.00709 Hom.: 0

Bravo AF: 0.0127

Asia WGS AF: 0.00491 AC: 17 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

May 24, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
Cadd	Benign	8.6
Dann	Benign	0.64

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.15		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

Other links and lift over

dbSNP: rs114438192; hg19: chr9-33113740;