In cystic fibrosis, a defect (mutation) in a gene changes a protein that regulates the movement of salt in and out of cells. The result is thick, sticky mucus in the respiratory, digestive and reproductive systems, as well as increased salt in sweat. Many different defects can occur in the gene. The type of gene mutation is associated with the severity of the condition.

The affected gene, which is inherited from a child's parents, is a recessive gene. Children need to inherit one copy of the gene from each parent in order to have the disease. If children inherit only one copy, they won't develop cystic fibrosis, but will be carriers and possibly pass the gene to their own children.

Jun. 13, 2012

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