Abstract
Background and objectives: Cystic fibrosis (CF) is the most common severe lethal autosomal recessive genetic disorder in Caucasians. This disease is caused by abnormal flow of electrolytes across the apical membranes of epithelial cells, which appears with elevated levels of Cl- and Na+ in sweat, dysfunction of lung, pancreatic, gastrointestinal, reproductive and hepatic systems. CF has the incidence of approximately 1 in 2500 live birth. Responsible gene for CF is cftr gene located on human chromosome 7 including 27 exons. The results obtained from the studying of exon 10 indicated that there are many affected families from this region with unknown mutations. Therefore it was necessary to study the mutation of other exons in these families. This study could be applied to estimate the mutation rates of these exons in the studied population and also diagnose carriers and affected pregnancies.
Materials and Methods: 48 affected families were referred by specialists to genetic center. DNA was extracted from peripheral blood of the patients and their parents. Then PCR was carried out and cftr gene analyzed for exons of 7, 11, 13, 17b, 19 and 21 by SSCP/Hd technique.
Results: The difference in SSCP pattern of exon 7 observed in one of the families. SSCP pattern was different in exon 11 of 9 families. The difference in SSCP pattern of exons 13, 19, 20 was observed in 2, 2 and 1 families respectively. SSCP pattern of exon 17 didn’t show difference in any families.
Conclusion: High heterogeneity was observed for the mutations of cftr gene in North-West population. Exon 11 showed more difference then other exons according to this study.