One of the disorder with single genetic autosomal recessive mode of inheritance that affects the respiratory system is Cystic Fibrosis (CF). This disease is mostly observed in Caucasians, and is caused by a variant in a gene located on the long arm of chromosome 7(7q31). The gene which is associated with this disease is cystic fibrosis transmembrane regulator (CFTR) gene. It codes for chloride transport and helps in mucin secretion through the epithelial cells of the nasopharynx and also in cytophysiological regulation of mucous transport. Mutation in this gene causes excess secretion of gelatinized mucin, and failure of mucous transport which causes accumulation of mucous plaques in lungs which leads to inflammation in the alveoli. This accumulation of mucin causes rapid development of severity of bacterial infections by micro organisms like Pseudomonas aeruginosa and Asperigillus fumigatus which become lethal due to respiratory failure.