A Perspective on Diverse Phenotypic Expression of Two Siblings Affected by Cystic Fibrosis with Homozygous F508del Genotype

Cystic Fibrosis (CF) is a single gene recessive genetic disorder caused by mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and has been estimated to have a prevalence of 1/25000 live births in Caucasians [1,2]. Recently, there has been substantial progress in the knowledge of CF as well as identification of more than 1,800 mutations in the CFTR gene that play a role in the phenotypic characterization of the disease. We describe a case of 2 Cystic Fibrosis siblings have markedly different clinical courses throughout their life. To objectively measure differences in their clinical courses, we reviewed clinical data points, chest x-rays and lung function tests [3].