rs1555016589

Positions:

• chr11-66347086-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_006876.3(B4GAT1):​c.460G>T​(p.Ala154Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000007 in 1,429,572 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: B4GAT1 NM_006876.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.49

Genes affected

B4GAT1 (HGNC:15685): (beta-1,4-glucuronyltransferase 1) This gene encodes a member of the beta-1,3-N-acetylglucosaminyltransferase family. This enzyme is a type II transmembrane protein. It is essential for the synthesis of poly-N-acetyllactosamine, a determinant for the blood group i antigen. [provided by RefSeq, Jul 2008]

ACMG classification

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=0.09891659).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
B4GAT1	NM_006876.3	c.460G>T	p.Ala154Ser	missense_variant	1/2	ENST00000311181.5	NP_006867.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
B4GAT1	ENST00000311181.5	c.460G>T	p.Ala154Ser	missense_variant	1/2	1	NM_006876.3	ENSP00000309096	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.00e-7 AC: 1 AN: 1429572 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 707942

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: 9.12e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

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 A13 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 27, 2017

This sequence change replaces alanine with serine at codon 154 of the B4GAT1 protein (p.Ala154Ser). The alanine residue is moderately conserved and there is a moderate physicochemical difference between alanine and serine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with a B4GAT1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. In summary, this variant has uncertain impact on B4GAT1 function. The available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.068
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.53
CADD	Benign	19
DANN	Benign	0.93
DEOGEN2	Benign	0.15	T
Eigen	Benign	-0.41
Eigen_PC	Benign	-0.15
FATHMM_MKL	Uncertain	0.83	D
LIST_S2	Benign	0.77	T
M_CAP	Benign	0.0058	T
MetaRNN	Benign	0.099	T
MetaSVM	Benign	-0.99	T
MutationTaster	Benign	0.68	D
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	1.1	N
REVEL	Benign	0.082
Sift	Benign	0.86	T
Sift4G	Benign	0.87	T
Polyphen		0.040	B
Vest4		0.31
MutPred		0.43		Gain of disorder (P = 0.0562);
MVP		0.030
MPC		0.77
ClinPred		0.77	D
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.079
gMVP		0.47

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: rs1555016589; hg19: chr11-66114557;