biological explanation

• condition is present at birth due to a defect in a gene on chromosome 7 that controls movement of salt and water in and out of cells in body
• the protein that is produced by gene causes mucus secreting cells to make sticky mucus instead of normal runny type
• this along with recurrent infections results in build up sticky mucus in lungs and digestive system
• there is no cure, over years lungs become increasingly damaged and may eventually stop working properly
• average life expectancy reduced for people with cf however, most individuals lead fulfilling lives with successful careers, family life and leisure activities