rs374533716

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBS1_Supporting

The NM_006876.3(B4GAT1):​c.447G>T​(p.Met149Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000107 in 1,582,022 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 (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000063 ( 0 hom. )

Consequence

B4GAT1
NM_006876.3 missense

Scores

2
16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 1.32

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 -5 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.0227184).
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.0000525 (8/152240) while in subpopulation AFR AF = 0.000193 (8/41476). AF 95% confidence interval is 0.0000956. There are 0 homozygotes in GnomAd4. There are 4 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
B4GAT1NM_006876.3 linkc.447G>T p.Met149Ile missense_variant Exon 1 of 2 ENST00000311181.5 NP_006867.1 O43505A0A024R5F9

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
B4GAT1ENST00000311181.5 linkc.447G>T p.Met149Ile missense_variant Exon 1 of 2 1 NM_006876.3 ENSP00000309096.4 O43505

Frequencies

GnomAD3 genomes
AF:
0.0000525
AC:
8
AN:
152240
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000193
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000286
AC:
6
AN:
209752
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.000453
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000629
AC:
9
AN:
1429782
Hom.:
0
Cov.:
31
AF XY:
0.00000141
AC XY:
1
AN XY:
708096
show subpopulations
African (AFR)
AF:
0.000243
AC:
8
AN:
32954
American (AMR)
AF:
0.0000237
AC:
1
AN:
42216
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24464
East Asian (EAS)
AF:
0.00
AC:
0
AN:
38948
South Asian (SAS)
AF:
0.00
AC:
0
AN:
82274
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48108
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5650
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1096206
Other (OTH)
AF:
0.00
AC:
0
AN:
58962
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.558
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000525
AC:
8
AN:
152240
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
AN XY:
74380
show subpopulations
African (AFR)
AF:
0.000193
AC:
8
AN:
41476
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.00
Hom.:
0
Bravo
AF:
0.0000756
ESP6500AA
AF:
0.000229
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000250
AC:
3

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Nov 08, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.447G>T (p.M149I) 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 447, causing the methionine (M) at amino acid position 149 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Aug 14, 2019
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The majority of missense variants in this gene are considered pathogenic (Stenson et al., 2014); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A13 Uncertain:1
Jul 17, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The isoleucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 1304862). This variant has not been reported in the literature in individuals affected with B4GAT1-related conditions. This variant is present in population databases (rs374533716, gnomAD 0.03%). This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 149 of the B4GAT1 protein (p.Met149Ile). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.19
BayesDel_addAF
Benign
-0.49
T
BayesDel_noAF
Benign
-0.61
CADD
Benign
17
DANN
Benign
0.93
DEOGEN2
Benign
0.15
T
Eigen
Benign
-0.69
Eigen_PC
Benign
-0.41
FATHMM_MKL
Uncertain
0.77
D
LIST_S2
Benign
0.67
T
M_CAP
Benign
0.0055
T
MetaRNN
Benign
0.023
T
MetaSVM
Benign
-0.99
T
PhyloP100
1.3
PrimateAI
Uncertain
0.62
T
PROVEAN
Benign
1.6
N
REVEL
Benign
0.060
Sift
Benign
0.81
T
Sift4G
Benign
0.91
T
Polyphen
0.0
B
Vest4
0.12
MutPred
0.43
Loss of disorder (P = 0.0727);
MVP
0.014
MPC
0.92
ClinPred
0.030
T
GERP RS
3.5
Varity_R
0.19
gMVP
0.75
Mutation Taster
=80/20
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

Publications

Other links and lift over

dbSNP: rs374533716; hg19: chr11-66114570; API