rs387907128
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP5
The NM_145239.3(PRRT2):c.796C>T(p.Arg266Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,630 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R266Q) has been classified as Likely benign.
Frequency
Consequence
NM_145239.3 missense
Scores
Clinical Significance
Conservation
Publications
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ACMG classification
Our verdict: Uncertain_significance. The variant received 1 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| PRRT2 | ENST00000358758.12 | c.796C>T | p.Arg266Trp | missense_variant | Exon 2 of 4 | 1 | NM_145239.3 | ENSP00000351608.7 | ||
| ENSG00000280893 | ENST00000609618.2 | n.796C>T | non_coding_transcript_exon_variant | Exon 2 of 6 | 5 | ENSP00000476774.2 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152136Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251012 AF XY: 0.00000737 show subpopulations
GnomAD4 exome AF: 0.00000753 AC: 11AN: 1461494Hom.: 0 Cov.: 35 AF XY: 0.00000413 AC XY: 3AN XY: 727070 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152136Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74318 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Episodic kinesigenic dyskinesia 1 Pathogenic:2
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not specified Uncertain:1
Variant summary: PRRT2 c.796C>T (p.Arg266Trp) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 4e-06 in 251012 control chromosomes. c.796C>T has been observed in individual(s) affected with Episodic Kinesigenic Dyskinesia 1 (Wang_2011, internal data), epilepsy and/or neurodevelopmental disorders (Lindy_2018), and self-limited infantile epilepsy (Tian_2023). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function, however, does not allow convincing conclusions about the variant effect (Zhao_2020). The following publications have been ascertained in the context of this evaluation (PMID: 31589614, 29655203, 32906206, 22120146, 31124310, 37880614). ClinVar contains an entry for this variant (Variation ID: 31177). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
Episodic kinesigenic dyskinesia Uncertain:1
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 266 of the PRRT2 protein (p.Arg266Trp). This variant is present in population databases (rs387907128, gnomAD 0.0009%). This missense change has been observed in individuals with paroxysmal kinesigenic dyskinesia (PMID: 22120146; Invitae). ClinVar contains an entry for this variant (Variation ID: 31177). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on PRRT2 protein function. Experimental studies have shown that this missense change does not substantially affect PRRT2 function (PMID: 31124310, 37271286). This variant disrupts the p.Arg266 amino acid residue in PRRT2. Other variant(s) that disrupt this residue have been observed in individuals with PRRT2-related conditions (PMID: 22120146, 26446061; Invitae), which suggests that this may be a clinically significant amino acid residue. 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