Clinical features in familial cases of Crohn's disease and ulcerative colitis in Italy: a GISC study. Italian Study Group for the Disease of Colon and Rectum.

Previous studies have reported genetic anticipation, genomic imprinting, and phenotypic concordance of some clinical features in familial cases of Crohn's disease (CD) and ulcerative colitis (UC). The aim of our study was to investigate the phenotypic features of affected members in a large sample of CD and UC Italian families. In a multicenter study, CD and UC families were recruited. Affected members were questioned about date of birth, gender, age at onset of symptoms and at diagnosis, location and extension of disease, occurrence of extraintestinal manifestations, use of steroids and/or of immunosuppressive drugs, need for resective surgery, and number of relapses per year (< 1 yr or > or = 1 yr). Statistical analysis was performed with chi2, Fisher's, Mann-Whitney U, and binomial probability tests, when appropriate. A total of 128 families with 270 affected members were studied: 35 were CD, 64 UC, and 29 mixed families (when UC and CD affected different members). In 99 of 128 families (77%), the diagnosis was concordant. In CD families, a high concordance for localization (46%), extraintestinal manifestations (67%), need for steroids (77%), need for immunosuppressive drugs (100%), need for surgery (29%), and relapse rate (36%) was found. In UC families, a high concordance for disease extension (33%), need for steroids (47%), and relapse rate (34%) was disclosed. A higher than expected concordance for ileal localization (p < 0.4) in CD families and extensive colitis (p < 0.05) in UC families was demonstrated. A generation difference of 15-20 yr in mean ages at onset of symptoms and at diagnosis was recorded. No features of more aggressive disease in subsequent generations and no differences in gender of transmitting parents and relatives were found. Our study shows a high rate of concordance for diagnosis and clinical features in UC and, especially, CD families. The disease occurred 15-20 yr earlier than in previous generations without features of increased severity.