Test Details: Cystic fibrosis (CF) is an autosomal recessive genetic disorder characterized by pulmonary and gastrointestinal symptoms of varying severity. It is caused by mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene coding for the main chloride channel in the epithelial cells. Mutation in the CFTR gene results in decreased chloride secretions and increased viscosity of extracellular fluids followed by duct obstruction and subsequent organ dysfunction. The predominant symptoms include progressive decline in pulmonary function leading to recurrent lower respiratory tract infection. The estimated prevalence of CF in Indians is reported to be in the range of 1:10000 to 1:40000. When both Parents are carriers, there is 50% probability of the offspring being a carrier and 25% risk of diseased offspring, at each conception. About 1200 CFTR mutations have been identified in CF. F508del is a relatively common mutation reported in the Indian CF patients (19-38%).