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
Consequence
NM_006876.3 missense
Scores
Clinical Significance
Conservation
Publications
- muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A13Inheritance: AR Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
- muscular dystrophy-dystroglycanopathy, type AInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_benign. The variant received -5 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt | 
|---|---|---|---|---|---|---|---|---|
| B4GAT1 | NM_006876.3 | c.447G>C | p.Met149Ile | missense_variant | Exon 1 of 2 | ENST00000311181.5 | NP_006867.1 | 
Ensembl
Frequencies
GnomAD3 genomes  0.000118  AC: 18AN: 152240Hom.:  0  Cov.: 32 show subpopulations 
GnomAD2 exomes  AF:  0.0000477  AC: 10AN: 209752 AF XY:  0.0000522   show subpopulations 
GnomAD4 exome  AF:  0.000203  AC: 290AN: 1429782Hom.:  0  Cov.: 31 AF XY:  0.000203  AC XY: 144AN XY: 708096 show subpopulations 
Age Distribution
GnomAD4 genome  0.000118  AC: 18AN: 152240Hom.:  0  Cov.: 32 AF XY:  0.000108  AC XY: 8AN XY: 74380 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
not provided    Uncertain:2 
- -
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 
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 
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: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at