Cystic fibrosis in Canadian Hutterites.

Background: The Hutterite Brethren are a communal group of Anabaptists who live in the Western regions of North America, predominantly in the Western Canadian provinces. Due to a founder effect, Hutterites have a high rate of cystic fibrosis (CF) with genotypes limited to only two CFTR mutations. One-third of Hutterite patients with CF are pancreatic sufficient. Previously we found an unexplained younger age at death in Hutterites compared with nonHutterites homozygous for the common F508del mutation. The present study expanded the data collection and analysis for confirmation and further exploration.

Methods: Anonymized information, based on Hutterite surnames, was extracted from the Canadian CF Registry. Summary data on nonHutterite patients with CF homozygous for F508del served as control. Statistical analyses explored the effects of genotype within Hutterites and compared nutritional status, lung function, and microbiologic findings between the groups.

Results: The younger average age at death in Hutterites compared with controls was confirmed, but there was no suggestion of a generally shortened life expectancy. While the nutritional status in Hutterite children was better than that of controls, their lung function was slightly but significantly lower. Staphylococcus aureus was more frequent in Hutterites while there was no difference between the groups regarding Pseudomonas aeruginosa.

Conclusions: Despite less pancreatic insufficiency, better nutrition, communal life in socioeconomic stability, and without exposure to environmental tobacco smoke, the clinical course of CF appears to be more severe in a significant number of Hutterites. Investigations of gene-environment interactions and of CF disease gene modifiers may help to explain this conundrum.