Phenotypic overlap among paroxysmal dyskinesia subtypes: Lesson from a family with PRRT2 gene mutation.
Paroxysmal dyskinesia (PD) is a group of rare neurological conditions which was divided into paroxysmal kinesigenic dyskinesia (PKD), paroxysmal non-kinesigenic dyskinesia (PNKD) and paroxysmal exercise-induced dyskinesia (PED) according to their clinical features. PRRT2 gene was initially identified as the major gene responsible for PKD followed by presence of various PRRT2 mutations discovered in families with benign familial infantile convulsions (BFIC) and infantile convulsions and choreoathetosis (ICCA). We describe a family with characteristic PD showing overlaps in clinical pictures among the three PD subgroups, and a nonsense PRRT2 mutation c.649C>T (p.Arg217X) was also detected. This broadens the phenotypic spectrum in PRRT2-related disorders. In addition, an unusual exercise trigger observed in the proband, likely representing an underestimated occurrence, together with the current clinical PD classification is also elucidated.
Department of Neurology, The First Affiliated Hospital, School of Medicine, Zhejiang University, China.
Kang
K
Wang
Xiaoyu
X
Zhao
Yue
Y
Du
Fangping
F
He
Guoping
G
Peng
Benyan
B
Luo
D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D002819:Chorea / Q000235:genetics* / Q000503:physiopathology; D018389:Codon, Nonsense; D004252:DNA Mutational Analysis; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype
D018389:Codon, Nonsense; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C569370:PRRT2 protein, human