title: [Influence of consanguinity on clinical characteristics and affective disorders frequency in relatives of bipolar I patients].
abstract: BACKGROUND
  The genetic transmission of bipolar disorder remained undetermined up to now, partly due to clinical and genetically heterogeneity. In Tunisia, genetic study will profit from the existence of high rates of consanguinity.
  
  
  OBJECTIVE
  To determine the rate of consanguinity in bipolar I disorders sample and to compare the clinical characteristics and the frequency of affective disorders in first and second degree relatives of probands with and without consanguinity.
  
  
  METHODS
  One hundred thirty subjects met DSM-IV criteria for a bipolar I disorder were recruited. Available Information was obtained from a structured clinical interview, collateral history and medical records. The family investigation allowed completion of genealogies over three generations. The comparison was based on the clinical characteristics (age of onset, numbers of affective episodes, nature and severity of the last affective episode) and the frequency of affective disorders in first and second degree relatives of probands with and without consanguinity.
  
  
  RESULTS
  the rate of consanguinity was estimated to 28,5% It was higher in patients with family history of affective disorders : 34,2% versus 20,4% (p=0,08). Bipolar I patients with consanguinity were characterised by a high frequency of affective episodes and a more severe of the last affective episode, but theses differences were not significantly. However, the frequency of affective disorders was significantly increased in first degree relatives of probands with consanguinity: 10,5% versus 6,1% (p=0,01), and in first and second degree relatives of probands with consanguinity : 4,5% versus 29% (p=0,02).
  
  
  CONCLUSIONS
  The influence of consanguinity on the clinical characteristics and the frequency of affective disorders in first and second degree relatives of bipolar patients is en favour the recessive polygenetic transmission of bipolar disorders.
authors.affiliation: Laboratoire de recherche Vulnérabilité aux psychoses, Service de Psychiatrie, hôpital universitaire de Monastir, Monastir, Tunisie.
authors.forename: Anwar
authors.initials: A
authors.lastname: Mechri
authors.forename: Khadija
authors.initials: K
authors.lastname: Rouissi
authors.forename: Boutheina
authors.initials: B
authors.lastname: Mehdi
authors.forename: Geneviève
authors.initials: G
authors.lastname: Khiari
authors.forename: Sonia
authors.initials: S
authors.lastname: Abdelhak
authors.forename: Lotfi
authors.initials: L
authors.lastname: Gaha
mesh_terms: D000293:Adolescent; D000328:Adult; D000341:Affective Disorders, Psychotic / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D017668:Age of Onset; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D003241:Consanguinity; D003430:Cross-Sectional Studies; D006801:Humans; D015994:Incidence; D010375:Pedigree; D011795:Surveys and Questionnaires; D014416:Tunisia / Q000453:epidemiology