Several siblings with Cystic Fibrosis as a risk factor for poor outcome

SummaryBackgroundOccurrence of Cystic Fibrosis (CF) in more than one member in a family is not uncommon. The aim of our study was to assess the influence of multiple siblings with CF on disease expression and outcome.MethodsStudy group consisted of 2-siblings (2-sibs, n = 42) or 3/4 siblings (3/4-sibs, n = 22) with CF in one family. Each sibling was matched by age, mutation, and gender to a single CF patient.Results3/4-sibs subgroup compared to singles showed a lower mean FEV1 with a faster decline rate (58.4 ± 27.5 vs. 72.7 ± 25.4 and −5 ± 6.4 vs. −1.7 ± 2.8 %predicted decline/year respectively, p < .05), more airway colonization by Pseudomonas aeruginosa and Mycobacterium abscessus (15 (68%) vs. 8 (36%) and 7 (32%) vs. 4 (18%), respectively, p < .05) and more lung transplants (5 (23%) vs. 2 (9%), respectively, p < .02). Last mean FEV1 within 3/4-sibs was significantly lower for the youngest sib (p < .05).ConclusionsThree or more CF patients in one family may be a risk factor for more severe disease and poor prognosis. In our view this reflects the burden of disease on the patients and families