chr11-66347086-C-A

Variant names:

• chr11-66347086-C-A
• rs1555016589
• NM_006876.3:c.460G>T

Variant summary

Our verdict is Uncertain significance. The variant received 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. 14/21 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, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.49
• Publications: 0 publications found

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]

B4GAT1 Gene-Disease associations (from GenCC):

• muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A13

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
• muscular dystrophy-dystroglycanopathy, type A

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.09891659).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006876.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	B4GAT1	NM_006876.3	MANE Select	c.460G>T	p.Ala154Ser	missense	Exon 1 of 2	NP_006867.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	B4GAT1	ENST00000311181.5	TSL:1 MANE Select	c.460G>T	p.Ala154Ser	missense	Exon 1 of 2	ENSP00000309096.4

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

African (AFR) AF: 0.00 AC: 0 AN: 33010

American (AMR) AF: 0.00 AC: 0 AN: 42598

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24406

East Asian (EAS) AF: 0.00 AC: 0 AN: 39132

South Asian (SAS) AF: 0.00 AC: 0 AN: 81958

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 46976

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5646

European-Non Finnish (NFE) AF: 9.12e-7 AC: 1 AN: 1096814

Other (OTH) AF: 0.00 AC: 0 AN: 59032

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Aug 09, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.460G>T (p.A154S) alteration is located in exon 1 (coding exon 1) of the B4GAT1 gene. This alteration results from a G to T substitution at nucleotide position 460, causing the alanine (A) at amino acid position 154 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A13 Uncertain:1

Jun 27, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 v4.9

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
PhyloP100		2.5
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
Mutation Taster		=91/9	polymorphism

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

Other links and lift over

dbSNP: rs1555016589; hg19: chr11-66114557;