CF..is an autosomal reccessive disorder of the exocrine glands affecting multiple organs mainly the lungs,pancrease and the liver..due to a defect in the CFRT GENE DIAGNOSIS OF CF INCLUDE: either positivegenetic testing or positive sweat chloride testfindings and one of the followings:*typical copd*doucmented exocrine pancreatic insufficincy*positive family history...immaging that may be helpfull .are radiology of chest,sinusis,abdomen,ctsccaning of the chest,ultrasonography of abdomen,and contrast barium enema the main defferential diagnosis include:aspergillosis,tuberclosis,bronchiactasis,bronchiolitis,primary cilliary dyskinasia,failure to thrive,short stuture wegners granulomatosis and sinusitis