Cystic fibrosis mutations in French Canadians: three CFTR mutations are relatively frequent in a Quebec population with an elevated incidence of cystic fibrosis.
The French-Canadian population in the Saguenay-Lac St. Jean region of northeastern Quebec has an elevated frequency of cystic fibrosis (CF). The average incidence of cystic fibrosis was 1 in 891 births and the prevalence of CF carriers was estimated to be 1 in 15. We tested for 10 mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 133 French-Canadian CF families from Quebec. Ninety-one families were from the Saguenay-Lac St. Jean region and 42 families were referred from other regions of Quebec. We detected the CFTR mutation in 93 and 92% of the CF chromosomes in the Saguenay-Lac St. Jean and the major-urban Quebec families, respectively. The two groups of French-Canadian families were significantly different for the proportions of CFTR mutations. The three most common mutations in the Saguenay-Lac St. Jean families were delta F508 (58%), 621 + 1G----T (23%), and A455E (8%); and in the major-urban Quebec families were delta F508 (71%), 711 + 1G----T (9%), and 621 + 1G----T (5%). These results provide evidence for the role of founder effect in the elevated incidence of cystic fibrosis in the Saguenay-Lac St. Jean population.
Rozen
R
R
Department of Pediatrics, McGill University, Montreal, Quebec, Canada.
De Braekeleer
M
M
Daigneault
J
J
Ferreira-Rajabi
L
L
Gerdes
M
M
Lamoureux
L
L
Aubin
G
G
Simard
F
F
Fujiwara
T M
TM
Morgan
K
K
D003550:Cystic Fibrosis / Q000208:ethnology / Q000235:genetics*; D004252:DNA Mutational Analysis; D005838:Genotype; D006801:Humans; D009154:Mutation / Q000235:genetics*; D011792:Quebec