Cystic fibrosis

• • Cystic fibrosis is a genetic disorder of cell membranes
  • It results in the body producing large amounts of thick, sticky mucus in the air passages
  • Over time, this may damage the lungs and stop them from working properly
  • Cystic fibrosis is caused by a recessive allele (f)
• • This means:
  • People who are heterozygous (only carry one copy of the recessive allele) won’t be affected by the disorder but are ‘carriers’
  • People must be homozygous recessive (carry two copies of the recessive allele) in order to have the disorder
  • If both parents are carriers, the chance of them producing a child with cystic fibrosis is 1 in 4, or 25%
  • If only one of the parents is a carrier (with the other parent being homozygous dominant), there is no chance of producing a child with cystic fibrosis