chr11-66346484-G-C

Variant names:

• chr11-66346484-G-C
• rs1555016387
• NM_006876.3:c.1056+6C>G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_006876.3(B4GAT1):​c.1056+6C>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000188 in 1,595,426 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: B4GAT1 NM_006876.3 splice_region, intron
• Scores: Splicing: ADA: 0.0001984
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: -0.222
• 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: ClinGen, Labcorp Genetics (formerly Invitae)
• muscular dystrophy-dystroglycanopathy, type A

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.89).
• BP6: Variant 11-66346484-G-C is Benign according to our data. Variant chr11-66346484-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 507234.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	B4GAT1	NM_006876.3	MANE Select	c.1056+6C>G		splice_region intron	N/A	NP_006867.1	O43505

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	B4GAT1	ENST00000311181.5	TSL:1 MANE Select	c.1056+6C>G		splice_region intron	N/A	ENSP00000309096.4	O43505
	B4GAT1	ENST00000865226.1		c.1002+60C>G		intron	N/A	ENSP00000535285.1

Frequencies

GnomAD3 genomes AF: 0.00000659 AC: 1 AN: 151826 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000139 AC: 2 AN: 1443482 Hom.: 0 Cov.: 31 AF XY: 0.00000140 AC XY: 1 AN XY: 714944

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33248

American (AMR) AF: 0.00 AC: 0 AN: 44126

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25084

East Asian (EAS) AF: 0.0000254 AC: 1 AN: 39388

South Asian (SAS) AF: 0.00 AC: 0 AN: 84202

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52500

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5666

European-Non Finnish (NFE) AF: 9.09e-7 AC: 1 AN: 1099706

Other (OTH) AF: 0.00 AC: 0 AN: 59562

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0448430), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151944 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74262

African (AFR) AF: 0.00 AC: 0 AN: 41418

American (AMR) AF: 0.00 AC: 0 AN: 15258

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5170

South Asian (SAS) AF: 0.00 AC: 0 AN: 4808

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10526

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67982

Other (OTH) AF: 0.00 AC: 0 AN: 2110

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	-	Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A13 (1)
-	-	1	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.89
CADD	Benign	1.6
DANN	Benign	0.60
PhyloP100		-0.22

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00020
dbscSNV1_RF	Benign	0.15
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: rs1555016387; hg19: chr11-66113955;