title: Risk of associated conditions in relatives of subjects with interstitial cystitis.
abstract: OBJECTIVE
  Urological chronic pelvic pain syndrome includes interstitial cystitis/painful bladder syndrome (IC/PBS), a chronic bladder pain condition of unknown etiology. Interstitial cystitis/painful bladder syndrome can co-occur with a number of associated conditions such as irritable bowel syndrome and fibromyalgia. The purpose of this study was to estimate the heritability of approximately 20 associated conditions in first-degree relatives (and if appropriate, second- and third-degree relatives) of patients with IC/PBS to identify shared genetic contributions for the disease combinations.
  
  
  METHODS
  We used the Utah Population Database, a unique population-based genealogical database that has been linked to electronic health records for the University of Utah Health Sciences Center back in 1994. Interstitial cystitis/painful bladder syndrome probands were identified by the International Classification of Diseases, Ninth Revision code for chronic interstitial cystitis and had genealogy information for 12 of their 14 immediate ancestors. We calculated excess risk of an associated condition in relatives of patients with IC/PBS using relative risk estimates.
  
  
  RESULTS
  We identified 248 IC/PBS probands. We found that 2 associated conditions, myalgia and myositis/unspecified (fibromyalgia) as well as constipation, were in significant excess in the patients with IC/PBS themselves, their first-degree relatives, and their second-degree relatives. The excess risk among relatives between IC/PBS and these associated conditions also held in the converse direction. Excess risk of IC/PBS was observed in the first- and second-degree relatives in probands with myalgia and myositis/unspecified (fibromyalgia) and in probands with constipation.
  
  
  CONCLUSIONS
  These results suggest that myalgia and myositis/unspecified (fibromyalgia) as well as constipation are likely to share underlying genetic factors with IC/PBS.
authors.affiliation: From the Departments of *Internal Medicine, and †Obstetrics and Gynecology, University of Utah; and ‡George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT.
authors.forename: Kristina
authors.initials: K
authors.lastname: Allen-Brady
authors.forename: Peggy A
authors.initials: PA
authors.lastname: Norton
authors.forename: Lisa
authors.initials: L
authors.lastname: Cannon-Albright
mesh_terms: D015897:Comorbidity; D003248:Constipation / Q000453:epidemiology / Q000235:genetics*; D018856:Cystitis, Interstitial / Q000453:epidemiology / Q000235:genetics*; D005190:Family; D005260:Female; D005356:Fibromyalgia / Q000453:epidemiology / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D063806:Myalgia / Q000453:epidemiology / Q000235:genetics*; D009220:Myositis / Q000453:epidemiology / Q000235:genetics; D010375:Pedigree; D012306:Risk; D014589:Utah / Q000453:epidemiology