chr6-33277503-G-C

Position:

• chr6-33277503-G-C

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6_Moderate

The NM_003782.4(B3GALT4):​c.84G>C​(p.Leu28Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,400 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: B3GALT4 NM_003782.4 missense
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -1.99

Genes affected

B3GALT4 (HGNC:919): (beta-1,3-galactosyltransferase 4) This gene is a member of the beta-1,3-galactosyltransferase (beta3GalT) gene family. This family encodes type II membrane-bound glycoproteins with diverse enzymatic functions using different donor substrates (UDP-galactose and UDP-N-acetylglucosamine) and different acceptor sugars (N-acetylglucosamine, galactose, N-acetylgalactosamine). The beta3GalT genes are distantly related to the Drosophila Brainiac gene and have the protein coding sequence contained in a single exon. The beta3GalT proteins also contain conserved sequences not found in the beta4GalT or alpha3GalT proteins. The carbohydrate chains synthesized by these enzymes are designated as type 1, whereas beta4GalT enzymes synthesize type 2 carbohydrate chains. The ratio of type 1:type 2 chains changes during embryogenesis. By sequence similarity, the beta3GalT genes fall into at least two groups: beta3GalT4 and 4 other beta3GalT genes (beta3GalT1-3, beta3GalT5). This gene is oriented telomere to centromere in close proximity to the ribosomal protein S18 gene. The functionality of the encoded protein is limited to ganglioseries glycolipid biosynthesis. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.051751852).
• BP6: Variant 6-33277503-G-C is Benign according to our data. Variant chr6-33277503-G-C is described in ClinVar as [Likely_benign]. Clinvar id is 2544372.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
B3GALT4	NM_003782.4	c.84G>C	p.Leu28Phe	missense_variant	1/1	ENST00000451237.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
B3GALT4	ENST00000451237.3	c.84G>C	p.Leu28Phe	missense_variant	1/1		NM_003782.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460400 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726530

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: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

May 05, 2023

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.074
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.39
CADD	Benign	2.8
DANN	Benign	0.95
DEOGEN2	Benign	0.019	T
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.033	N
M_CAP	Benign	0.019	T
MetaRNN	Benign	0.052	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.34	N
MutationTaster	Benign	1.0	N
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	0.27	N
REVEL	Benign	0.031
Sift	Benign	0.20	T
Sift4G	Benign	0.13	T
Polyphen		0.0	B
Vest4		0.033
MutPred		0.34		Loss of catalytic residue at L28 (P = 0.1183);
MVP		0.30
MPC		0.86
ClinPred		0.086	T
GERP RS		-4.6
Varity_R		0.055
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

Other links and lift over

dbSNP: rs1374336222; hg19: chr6-33245280;