title: CYP2C19 polymorphism and risk for essential tremor.
abstract: Many patients with essential tremor (ET) develop acute adverse effects to primidone. We investigated the association between CYP2C19 polymorphism (possibly related to primidone metabolism) and the risk for developing essential ET and acute adverse effects to primidone. Leukocytary DNA from 200 ET patients and 300 healthy controls was studied for the genotype CYP2C19 and the occurrence of CYP2C19 allelic variants by using allele-specific PCR amplification and Sma I and BamH I RFLP analyses. The frequencies of the genotype CYP2C19*1/CYP2C19*2 and of the allelic variant CYP2C19*2 were significantly higher in ET patients than in controls. The mean age at onset of ET did not differ significantly between patients with genotypes CYP2C19*1/CYP2C19*2andCYP2C19*1/CYP2C19*1. The frequencies of the genotype CYP2C19*1/CYP2C19*2 and the allelic variant CYP2C19*2 were similar in ET patients who developed acute adverse effects to primidone, in those who tolerated primidone and in controls; the frequencies were also similar in patients with head, voice, tongue and chin tremor compared with controls. These results suggest that heterozygosis CYP2C19*1/CYP2C19*2 is associated with the risk for ET, but not with the age at onset of ET, the presentation of acute side effects of primidone, or the existence of head, voice, tongue or chin tremor.
authors.affiliation: Department of Medicine-Neurology, Hospital Príncipe de Asturias, Universidad de Alcalá, Alcalá de Henares, Spain.
authors.forename: Hortensia
authors.initials: H
authors.lastname: Alonso-Navarro
authors.forename: Carmen
authors.initials: C
authors.lastname: Martínez
authors.forename: Elena
authors.initials: E
authors.lastname: García-Martín
authors.forename: Julián
authors.initials: J
authors.lastname: Benito-León
authors.forename: Isabel
authors.initials: I
authors.lastname: García-Ferrer
authors.forename: Pilar
authors.initials: P
authors.lastname: Vázquez-Torres
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Puertas
authors.forename: Tomás
authors.initials: T
authors.lastname: López-Alburquerque
authors.forename: José A G
authors.initials: JA
authors.lastname: Agúndez
authors.forename: Félix Javier
authors.initials: FJ
authors.lastname: Jiménez-Jiménez
mesh_terms: D000328:Adult; D017668:Age of Onset; D000927:Anticonvulsants / Q000009:adverse effects; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D065731:Cytochrome P-450 CYP2C19; D004361:Drug Tolerance / Q000235:genetics; D020329:Essential Tremor / Q000188:drug therapy / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D006899:Mixed Function Oxygenases / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011324:Primidone / Q000009:adverse effects; D012307:Risk Factors
chemical_list: D000927:Anticonvulsants; D011324:Primidone; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19