RT Journal Article SR Electronic T1 Birth distribution in cystic fibrosis in Saguenay-Lac-St-Jean, Quebec, Canada. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 613 OP 614 DO 10.1136/jmg.28.9.613 VO 28 IS 9 A1 Daigneault, J A1 Aubin, G A1 Simard, F A1 De Braekeleer, M YR 1991 UL http://jmg.bmj.com/content/28/9/613.abstract AB Although a seasonal trend in the birth distribution has been reported in cystic fibrosis (CF), this finding is still very controversial. The birth distribution of 113 patients with cystic fibrosis born in Saguenay-Lac-St-Jean (complete ascertainment) was analysed using two different statistical methods. Our results showed no monthly or seasonal birth variation. It is likely that a bias owing to incomplete ascertainment might explain why some previous studies found a seasonal trend in the birth distribution of cystic fibrosis.