rs1553356208

Positions:

• chr1-235504243-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_152490.5(B3GALNT2):​c.10T>C​(p.Trp4Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000075 in 1,333,858 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.5e-7 (0 hom.)
• Consequence: B3GALNT2 NM_152490.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.24

Genes affected

B3GALNT2 (HGNC:28596): (beta-1,3-N-acetylgalactosaminyltransferase 2) This gene encodes a member of the glycosyltransferase 31 family. The encoded protein synthesizes GalNAc:beta-1,3GlcNAc, a novel carbohydrate structure, on N- and O-glycans. Alternatively spliced transcript variants that encode different isoforms have been described. [provided by RefSeq, Mar 2013]

B3GALNT2 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
B3GALNT2	NM_152490.5	c.10T>C	p.Trp4Arg	missense_variant	1/12	ENST00000366600.8	NP_689703.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
B3GALNT2	ENST00000366600.8	c.10T>C	p.Trp4Arg	missense_variant	1/12	1	NM_152490.5	ENSP00000355559.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.50e-7 AC: 1 AN: 1333858 Hom.: 0 Cov.: 33 AF XY: 0.00000152 AC XY: 1 AN XY: 657918

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type a, 11 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 24, 2020

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with B3GALNT2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces tryptophan with arginine at codon 4 of the B3GALNT2 protein (p.Trp4Arg). The tryptophan residue is weakly conserved and there is a moderate physicochemical difference between tryptophan and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.64
BayesDel_addAF	Uncertain	0.057	T
BayesDel_noAF	Benign	-0.16
CADD	Uncertain	24
DANN	Benign	0.97
DEOGEN2	Benign	0.051	T;.
Eigen	Uncertain	0.28
Eigen_PC	Uncertain	0.24
FATHMM_MKL	Benign	0.44	N
M_CAP	Pathogenic	0.87	D
MetaRNN	Uncertain	0.61	D;D
MetaSVM	Benign	-0.91	T
MutationAssessor	Benign	0.81	L;L
PrimateAI	Pathogenic	0.92	D
PROVEAN	Benign	-1.6	N;N
REVEL	Benign	0.25
Sift	Benign	0.047	D;.
Sift4G	Benign	0.069	T;D
Polyphen		0.93	P;D
Vest4		0.44
MutPred		0.73		Gain of methylation at W4 (P = 0.0139);Gain of methylation at W4 (P = 0.0139);
MVP		0.57
MPC		0.75
ClinPred		0.71	D
GERP RS		3.2
Varity_R		0.42
gMVP		0.68

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: rs1553356208; hg19: chr1-235667543;