20-763738-G-C
Variant summary
Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBS1_Supporting
The NM_033409.4(SLC52A3):c.833C>G(p.Thr278Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T278M) has been classified as Benign.
Frequency
Consequence
NM_033409.4 missense
Scores
Clinical Significance
Conservation
Publications
- Brown-Vialetto-van Laere syndrome 1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, ClinGen, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia
 - progressive bulbar palsyInheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
 
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ACMG classification
Our verdict: Likely_benign. The variant received -5 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes   AF:  0.0000394  AC: 6AN: 152186Hom.:  0  Cov.: 33 show subpopulations 
GnomAD2 exomes  AF:  0.0000119  AC: 3AN: 251306 AF XY:  0.00   show subpopulations 
GnomAD4 exome  AF:  0.00000958  AC: 14AN: 1461862Hom.:  0  Cov.: 35 AF XY:  0.00000550  AC XY: 4AN XY: 727238 show subpopulations 
Age Distribution
GnomAD4 genome   AF:  0.0000394  AC: 6AN: 152186Hom.:  0  Cov.: 33 AF XY:  0.0000404  AC XY: 3AN XY: 74340 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
Inborn genetic diseases    Uncertain:1 
The p.T278R variant (also known as c.833C>G), located in coding exon 2 of the SLC52A3 gene, results from a C to G substitution at nucleotide position 833. The threonine at codon 278 is replaced by arginine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Brown-Vialetto-van Laere syndrome 1    Uncertain:1 
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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SLC52A3 protein function. ClinVar contains an entry for this variant (Variation ID: 839471). This variant has not been reported in the literature in individuals affected with SLC52A3-related conditions. This variant is present in population databases (rs3746803, gnomAD 0.01%). This sequence change replaces threonine, which is neutral and polar, with arginine, which is basic and polar, at codon 278 of the SLC52A3 protein (p.Thr278Arg). -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at