rs367543075

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_152490.5(B3GALNT2):​c.824_825dupTT​(p.Ile276LeufsTer26) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000276 in 1,613,952 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 31)
Exomes 𝑓: 0.00029 ( 0 hom. )

Consequence

B3GALNT2
NM_152490.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9O:1

Conservation

PhyloP100: 0.678

Publications

4 publications found
Variant links:
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 Gene-Disease associations (from GenCC):
  • muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type a, 11
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics, Genomics England PanelApp
  • autosomal recessive non-syndromic intellectual disability
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • muscle-eye-brain disease
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • muscular dystrophy-dystroglycanopathy, type A
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • intellectual disability
    Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 1-235465651-T-TAA is Pathogenic according to our data. Variant chr1-235465651-T-TAA is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 132981.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
B3GALNT2NM_152490.5 linkc.824_825dupTT p.Ile276LeufsTer26 frameshift_variant Exon 7 of 12 ENST00000366600.8 NP_689703.1 Q8NCR0-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
B3GALNT2ENST00000366600.8 linkc.824_825dupTT p.Ile276LeufsTer26 frameshift_variant Exon 7 of 12 1 NM_152490.5 ENSP00000355559.3 Q8NCR0-1

Frequencies

GnomAD3 genomes
AF:
0.000125
AC:
19
AN:
152146
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000265
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000211
AC:
53
AN:
251380
AF XY:
0.000236
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000924
Gnomad NFE exome
AF:
0.000431
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000292
AC:
427
AN:
1461806
Hom.:
0
Cov.:
31
AF XY:
0.000257
AC XY:
187
AN XY:
727206
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39678
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.000131
AC:
7
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.000363
AC:
404
AN:
1111968
Other (OTH)
AF:
0.000232
AC:
14
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
25
49
74
98
123
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
20
40
60
80
100
<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:
0.000125
AC:
19
AN:
152146
Hom.:
0
Cov.:
31
AF XY:
0.0000942
AC XY:
7
AN XY:
74322
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41440
American (AMR)
AF:
0.00
AC:
0
AN:
15256
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000265
AC:
18
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.470
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.000291
Hom.:
0
EpiCase
AF:
0.000109
EpiControl
AF:
0.000237

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:9Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type a, 11 Pathogenic:6
Mar 30, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: B3GALNT2 c.824_825dupTT (p.Ile276LeufsX26) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 0.00021 in 251380 control chromosomes (gnomAD). c.824_825dupTT has been reported in the literature in the compound heterozygous state in individuals affected with and/or with features of Muscular Dystrophy-Dystroglycanopathy (congenital With Brain And Eye Anomalies) and in two siblings presenting with mild intellectual disability and behavioral problems but without muscular involvement (e.g. Stevens_2013, Maroofian_2017, Marangoni_2022). These data indicate that the variant is likely to be associated with disease. A publication reporting experimental evidence evaluating an impact on protein function found the variant failed to restore IIH6 staining in a complementation assay, resulting in <10% of WT activity (Maroofian_2017). Five submitters have provided clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as pathogenic (n=4)/likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as pathogenic. -

May 31, 2017
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 28, 2024
Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

second B3GALNT2 in trans (Missense-Variant, VUS) -

Oct 12, 2017
Genome Diagnostics Laboratory, Amsterdam University Medical Center
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 05, 2019
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 25, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Ile276Leufs*26) in the B3GALNT2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in B3GALNT2 are known to be pathogenic (PMID: 23453667). This variant is present in population databases (rs367543075, gnomAD 0.04%). This premature translational stop signal has been observed in individual(s) with congenital muscular dystrophy and/or congenital muscular dystrophy-dystroglycanopathy (PMID: 23453667, 29273094). It has also been observed to segregate with disease in related individuals. This variant is also known as c.822_823dup. ClinVar contains an entry for this variant (Variation ID: 132981). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:2Other:1
-
Leiden Muscular Dystrophy pages (B3GALNT2)
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

-
Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jul 07, 2025
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 29273094, 35456500, 31980526, 34906519, 23453667) -

B3GALNT2-related disorder Pathogenic:1
Jun 24, 2024
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The B3GALNT2 c.824_825dupTT variant is predicted to result in a frameshift and premature protein termination (p.Ile276Leufs*26). This variant has been reported in the compound heterozygous state to be causative for dystroglycanopathy in two unrelated families (Stevens et al. 2013. PubMed ID: 23453667; Maroofian et al. 2017. PubMed ID: 29273094). This variant is reported in 0.043% of alleles in individuals of European (Non-Finnish) descent in gnomAD. Frameshift variants in B3GALNT2 are expected to be pathogenic, and this variant has been interpreted as pathogenic by multiple independent submitters to the ClinVar database (https://www.ncbi.nlm.nih.gov/clinvar/variation/132981). Given all the evidence, we too interpret c.824_825dup (p.Ile276Leufs*26) as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
0.68
Mutation Taster
=7/193
disease causing (ClinVar)

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs367543075; hg19: chr1-235628968; API