chr16-29814418-TG-T
Variant summary
Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_ModeratePM2PP5
The NM_145239.3(PRRT2):c.971delG(p.Gly324GlufsTer13) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000187 in 1,608,246 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_145239.3 frameshift
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 5 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
PRRT2 | ENST00000358758.12 | c.971delG | p.Gly324GlufsTer13 | frameshift_variant | Exon 3 of 4 | 1 | NM_145239.3 | ENSP00000351608.7 | ||
ENSG00000280893 | ENST00000609618.2 | n.960delG | non_coding_transcript_exon_variant | Exon 3 of 6 | 5 | ENSP00000476774.2 |
Frequencies
GnomAD3 genomes AF: 0.0000132 AC: 2AN: 152064Hom.: 0 Cov.: 32
GnomAD4 exome AF: 6.87e-7 AC: 1AN: 1456182Hom.: 0 Cov.: 35 AF XY: 0.00000138 AC XY: 1AN XY: 724294
GnomAD4 genome AF: 0.0000132 AC: 2AN: 152064Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74272
ClinVar
Submissions by phenotype
not provided Pathogenic:2
Reported previously in a male patient with paroxysmal kinesigenic dyskinesia (PMID: 30386286); Identified in a patient with seizures referred for genetic testing at GeneDx (PMID: 29655203); Frameshift variant predicted to result in abnormal protein length as the last 17 amino acids are replaced with 12 different amino acids, and other similar variants have been reported in HGMD; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 30386286, 32613771, 31440721, 34926809, 36801247, 29655203) -
PRRT2: PM2, PS4:Moderate, PVS1:Moderate, PP4 -
Episodic kinesigenic dyskinesia 1 Pathogenic:1
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Seizures, benign familial infantile, 2 Pathogenic:1
The frameshift deletion p.G324Efs*13 in PRRT2 (NM_145239.2) has been observed before in a patient with paroxysmal kinesigenic dyskinesia (Liu YT et al). It has been submitted to ClinVar as Likely Pathogenic. Other missense variants occuring at this residue have been deemed to be disease causing (Tsai MH et al). The p.G324Efs*13 variant is novel not in any individuals) in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. This variant is predicted to cause loss of normal protein function through protein truncation caused a frameshift mutation. The frame shifted sequence continues 13 residues until a stop codon is reached. For these reasons, this variant has been classified as Pathogenic. -
Episodic kinesigenic dyskinesia Pathogenic:1
This sequence change creates a premature translational stop signal (p.Gly324Glufs*13) in the PRRT2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 17 amino acid(s) of the PRRT2 protein. This variant is present in population databases (rs796052941, gnomAD 0.01%). This premature translational stop signal has been observed in individual(s) with PRRT2-related conditions (PMID: 30386286). ClinVar contains an entry for this variant (Variation ID: 206696). This variant disrupts a region of the PRRT2 protein in which other variant(s) (p.Ile327Met) have been determined to be pathogenic (PMID: 2131349, 23496026, 24609974, 24886244). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Seizures, benign familial infantile, 2;C1865926:Infantile convulsions and choreoathetosis;C4552000:Episodic kinesigenic dyskinesia 1 Uncertain:1
PM2_Supporting+PVS1_Moderate+PS4_Supporting -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at