NM_006876.3:c.1056+6C>G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2BP4_StrongBP6

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

2
Splicing: ADA: 0.0001984
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:1

Conservation

PhyloP100: -0.222

Publications

0 publications found
Variant links:
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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
B4GAT1NM_006876.3 linkc.1056+6C>G splice_region_variant, intron_variant Intron 1 of 1 ENST00000311181.5 NP_006867.1 O43505A0A024R5F9

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
B4GAT1ENST00000311181.5 linkc.1056+6C>G splice_region_variant, intron_variant Intron 1 of 1 1 NM_006876.3 ENSP00000309096.4 O43505

Frequencies

GnomAD3 genomes
AF:
0.00000659
AC:
1
AN:
151826
Hom.:
0
Cov.:
32
show subpopulations
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
show subpopulations
⚠️ 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.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.350
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
151944
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74262
show subpopulations
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
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A13 Uncertain:1
Jul 12, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 1 of the B4GAT1 gene. It does not directly change the encoded amino acid sequence of the B4GAT1 protein. It affects a nucleotide within the consensus splice site. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with B4GAT1-related conditions. ClinVar contains an entry for this variant (Variation ID: 507234). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. 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. -

not specified Benign:1
Feb 06, 2017
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Computational scores

Source: dbNSFP v4.3

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

Publications

Other links and lift over

dbSNP: rs1555016387; hg19: chr11-66113955; API