11-66347099-C-G

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>C​(p.Met149Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000195 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 0.00012 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00020 ( 0 hom. )

Consequence

B4GAT1
NM_006876.3 missense

Scores

1
17

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

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=0.031127453).
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000118 (18/152240) while in subpopulation NFE AF = 0.000191 (13/68036). AF 95% confidence interval is 0.000112. There are 0 homozygotes in GnomAd4. There are 8 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>C 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>C p.Met149Ile missense_variant Exon 1 of 2 1 NM_006876.3 ENSP00000309096.4 O43505

Frequencies

GnomAD3 genomes
AF:
0.000118
AC:
18
AN:
152240
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000964
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.000191
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000477
AC:
10
AN:
209752
AF XY:
0.0000522
show subpopulations
Gnomad AFR exome
AF:
0.00
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:
0.000107
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000203
AC:
290
AN:
1429782
Hom.:
0
Cov.:
31
AF XY:
0.000203
AC XY:
144
AN XY:
708096
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32954
American (AMR)
AF:
0.00
AC:
0
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:
0.000260
AC:
285
AN:
1096206
Other (OTH)
AF:
0.0000848
AC:
5
AN:
58962
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
21
41
62
82
103
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:
0.000118
AC:
18
AN:
152240
Hom.:
0
Cov.:
32
AF XY:
0.000108
AC XY:
8
AN XY:
74380
show subpopulations
African (AFR)
AF:
0.0000964
AC:
4
AN:
41476
American (AMR)
AF:
0.0000654
AC:
1
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:
0.000191
AC:
13
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.494
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:
0.0000784
Hom.:
0
Bravo
AF:
0.0000756
TwinsUK
AF:
0.000539
AC:
2
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.0000584
AC:
7

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Dec 28, 2021
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 21, 2020
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); 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 -

Inborn genetic diseases Uncertain:1
Jul 05, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.447G>C (p.M149I) alteration is located in exon 1 (coding exon 1) of the B4GAT1 gene. This alteration results from a G to C 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. -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A13 Uncertain:1
Nov 08, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 577279). 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. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.19
BayesDel_addAF
Benign
-0.41
T
BayesDel_noAF
Benign
-0.61
CADD
Benign
17
DANN
Benign
0.88
DEOGEN2
Benign
0.15
T
Eigen
Benign
-0.69
Eigen_PC
Benign
-0.41
FATHMM_MKL
Benign
0.63
D
LIST_S2
Benign
0.67
T
M_CAP
Benign
0.0055
T
MetaRNN
Benign
0.031
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
0.043
T
GERP RS
3.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
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