title: CYP2D6 polymorphism is not associated with essential tremor.
abstract: Recent reports have shown an association between cytochrome P450IID6 (CYP2D6) polymorphism and Parkinson's disease. We investigated the association between this polymorphism and the risk for developing essential tremor (ET). Leukocytic DNA from 91 unrelated ET patients and a control group of 258 unrelated healthy individuals was studied for the occurrence of eight different CYP2D6 allelic variants by using allele-specific PCR amplification Xbal and EcoRI-RFLP's analyses. The prevalence for these allelic variants in the ET and control groups were, respectively: CYP2D6*1 76.9 and 78.7%, CYP2D6*2 0.5 and 0.2%, CYP2D6*3 0 and 1%, CYP2D6*4 12.1 and 12.2%, CYP2D6*5 1.6 and 1.7%, CYP2D6*9 4.4 and 2.9%, CYP2D6*2x2 4.4 and 3.2%. The prevalence of subjects with absent CYP2D6 activity (those carrying two defect genes) was 1.1 and 3.1% in ET and control groups, respectively. Both groups studied were in Hardy-Weinberg equilibrium. These results indicate that mutations at the CYP2D6 gene do not seem to be a major factor in determining susceptibility to ET, and reinforces the view that ET and parkinsonism are distinct conditions.
authors.affiliation: Department of Pharmacology and Psychiatry, Medical School, University of Extremadura, Badajoz, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Agúndez
authors.forename: F J
authors.initials: FJ
authors.lastname: Jiménez-Jiménez
authors.forename: R
authors.initials: R
authors.lastname: Tejeda
authors.forename: M C
authors.initials: MC
authors.lastname: Ledesma
authors.forename: M
authors.initials: M
authors.lastname: Ortí-Pareja
authors.forename: T
authors.initials: T
authors.lastname: Gasalla
authors.forename: J A
authors.initials: JA
authors.lastname: Molina
authors.forename: J
authors.initials: J
authors.lastname: Ruiz
authors.forename: F
authors.initials: F
authors.lastname: Coria
authors.forename: J
authors.initials: J
authors.lastname: Duarte
authors.forename: A
authors.initials: A
authors.lastname: Vázquez
authors.forename: J M
authors.initials: JM
authors.lastname: Ladero
authors.forename: J
authors.initials: J
authors.lastname: Benítez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D012307:Risk Factors; D014202:Tremor / Q000175:diagnosis / Q000235:genetics*
chemical_list: D019389:Cytochrome P-450 CYP2D6