title: Family studies in narcolepsy.
abstract: Out of a population of 188 unrelated narcoleptic probands, we identified 14 probands (7.44%) with a family history of narcolepsy, 23 (12.23%) with a family history of isolated repeated episodes of naps and/or lapses into sleep and 151 (80.31%) without a family history of either condition. Clinical, polysomnographic or zygotic differences could not be evidenced in the three groups. Empirical risk for narcolepsy was 40.7 times greater among first-degree relatives of narcoleptics than in the general population. Narcolepsy and the condition characterized by isolated repeated episodes of naps and/or lapses into sleep have a common genetic component. This finding has important implications. Indeed, when the latter condition is included in the spectrum of narcolepsy, the empirical risk figure is relatively close to that expected in cases of simple mode of inheritance. A trend in favor of a more frequent transmission through mothers than fathers is emphasized.
authors.affiliation: Service de Neurologie B, Hôpital Gui de Chauliac, Montpellier, France.
authors.forename: M
authors.initials: M
authors.lastname: Billiard
authors.forename: V
authors.initials: V
authors.lastname: Pasquié-Magnetto
authors.forename: M
authors.initials: M
authors.lastname: Heckman
authors.forename: B
authors.initials: B
authors.lastname: Carlander
authors.forename: A
authors.initials: A
authors.lastname: Besset
authors.forename: Z
authors.initials: Z
authors.lastname: Zachariev
authors.forename: J F
authors.initials: JF
authors.lastname: Eliaou
authors.forename: A
authors.initials: A
authors.lastname: Malafosse
mesh_terms: D017668:Age of Onset; D005190:Family; D005260:Female; D006680:HLA Antigens / Q000235:genetics; D006801:Humans; D008297:Male; D009290:Narcolepsy / Q000175:diagnosis / Q000235:genetics*; D010375:Pedigree; D017286:Polysomnography; D012895:Sleep, REM
chemical_list: D006680:HLA Antigens