title: The familial form of spondylarthropathy: a clinical study of 115 multiplex families. Groupe Français d'Etude Génétique des Spondylarthropathies.
abstract: OBJECTIVE
  To investigate the interrelationships among different phenotypes, and their relationship to the HLA-Blocus, in multiplex families with spondylarthropathy (SpA).
  
  
  METHODS
  We recruited 115 white French families, each of which had at least 2 members with SpA. Pedigrees were established. Clinical data and pelvic radiographs were collected. The HLA-B27 status of all patients was determined. Analysis was performed to determine the prevalence of SpA manifestations according to sex, disease duration, and HLA-B status, and to examine clustering of specific manifestations in subsets of families.
  
  
  RESULTS
  We identified 329 SpA patients. Mean +/-SD age at onset was 24+/-9.4 years. The male:female ratio was 186:143, or 1.3, with few sex differences in disease expression. Axial manifestations and HLA-B27 were each present in 97% of the patients. Inflammatory bowel disease and HLA-B35 were overrepresented in the 7 families containing HLA-B27-negative patients. The frequency of radiographic sacroiliitis increased in parallel with disease duration. Peripheral enthesitis, radiographic sacroiliitis, and psoriasis were evenly distributed in the families. Clustering independent of age was only observed for peripheral arthritis, suggesting that specific factors may predispose individuals to this manifestation.
  
  
  CONCLUSIONS
  Familial SpA appears to be homogeneous, based on the high frequencies of axial skeletal involvement and HLA-B27. The lack of clustering of most manifestations in families suggests that a predominant shared component, including HLA-B27, predisposes individuals to all forms of familial SpA, and that ubiquitous genetic or environmental factors contribute to phenotype diversity.
authors.affiliation: Cochin Hospital, Université René Descartes, Paris, France.
authors.forename: R
authors.initials: R
authors.lastname: Said-Nahal
authors.forename: C
authors.initials: C
authors.lastname: Miceli-Richard
authors.forename: J M
authors.initials: JM
authors.lastname: Berthelot
authors.forename: A
authors.initials: A
authors.lastname: Duché
authors.forename: E
authors.initials: E
authors.lastname: Dernis-Labous
authors.forename: G
authors.initials: G
authors.lastname: Le Blévec
authors.forename: A
authors.initials: A
authors.lastname: Saraux
authors.forename: A
authors.initials: A
authors.lastname: Perdriger
authors.forename: S
authors.initials: S
authors.lastname: Guis
authors.forename: P
authors.initials: P
authors.lastname: Claudepierre
authors.forename: J
authors.initials: J
authors.lastname: Sibilia
authors.forename: B
authors.initials: B
authors.lastname: Amor
authors.forename: M
authors.initials: M
authors.lastname: Dougados
authors.forename: M
authors.initials: M
authors.lastname: Breban
mesh_terms: D000328:Adult; D016000:Cluster Analysis; D005260:Female; D015235:HLA-B Antigens / Q000032:analysis; D059909:HLA-B14 Antigen; D015796:HLA-B27 Antigen / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D013122:Spinal Diseases / Q000150:complications / Q000235:genetics* / Q000276:immunology / Q000503:physiopathology; D013997:Time Factors
chemical_list: D015235:HLA-B Antigens; D059909:HLA-B14 Antigen; D015796:HLA-B27 Antigen