PRRT2 phenotypes and penetrance of paroxysmal kinesigenic dyskinesia and infantile convulsions

Rianne van Vliet, Guido Breedveld, Johanneke de Rijk-van Andel, Eva Brilstra, Nienke Verbeek, Cornien Verschuuren - Bemelmans, Maartje Boon, Johnny Samijn, Karin Diderich, Ingrid van de Laar, Ben Oostra, Vincenzo Bonifati, Anneke Maat-Kievit*

*Corresponding author for this work

    Research output: Contribution to journalArticleAcademicpeer-review

    51 Citations (Scopus)

    Abstract

    Objective: To describe the phenotypes and penetrance of paroxysmal kinesigenic dyskinesia (PKD), a movement disorder characterized by attacks of involuntary movements occurring after sudden movements, infantile convulsion and choreoathetosis (ICCA) syndrome, and benign familial infantile convulsions (BFIC), caused by PRRT2 mutations.

    Methods: We performed clinical and genetic studies in 3 large families with ICCA, 2 smaller families with PKD, and 4 individuals with sporadic PKD. Migraine was also present in several individuals.

    Results: We detected 3 different PRRT2 heterozygous mutations: the recurrent p.Arg217Profs*8 mutation, previously reported, was identified in 2 families with ICCA, 2 families with PKD, and one individual with sporadic PKD; one novel missense mutation (p.Ser275Phe) was detected in the remaining family with ICCA; and one novel truncating mutation (p.Arg217*) was found in one individual with sporadic PKD. In the 2 remaining individuals with sporadic PKD, PRRT2 mutations were not detected. Importantly, PRRT2 mutations did not cosegregate with febrile convulsions or with migraine. The estimated penetrance of PRRT2 mutations was 61%, if only the PKD phenotype was considered; however, if infantile convulsions were also taken into account, the penetrance was nearly complete. Considering our findings and those reported in literature, 23 PRRT2 mutations explain similar to 56% of the families analyzed.

    Conclusions: PRRT2 mutations are the major cause of PKD or ICCA, but they do not seem to be involved in the etiology of febrile convulsions and migraine. The identification of PRRT2 as a major gene for the PKD-ICCA-BFIC spectrum allows better disease classification, molecular confirmation of the clinical diagnosis, and genetic testing and counseling. Neurology (R) 2012;79:777-784

    Original languageEnglish
    Pages (from-to)777-784
    Number of pages8
    JournalNeurology
    Volume79
    Issue number8
    DOIs
    Publication statusPublished - Aug-2012

    Keywords

    • HUMAN-CHROMOSOME 16
    • CHOREOATHETOSIS
    • MUTATIONS
    • EPILEPSY
    • LINKAGE
    • FAMILY
    • LOCUS
    • CONFIRMATION
    • POPULATION
    • EXOCYTOSIS

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