What type of genetic disorder is cystic fibrosis?

Cystic fibrosis is classified as an autosomal recessive disorder. This means that an individual must inherit two copies of the defective gene, one from each parent, to express the disease. The gene involved in cystic fibrosis is the CFTR gene, which encodes a protein that helps regulate the movement of salt and water across cell membranes. When both copies of this gene are mutated, it leads to the production of thick and sticky mucus in various organs, particularly the lungs and digestive system, causing serious health complications.

Individuals who inherit only one copy of the mutated gene (carriers) do not exhibit symptoms of the disease, which further emphasizes how autosomal recessive inheritance works. The chance of two carriers having a child with cystic fibrosis is 25% with each pregnancy. This pattern of inheritance is key to understanding the genetic implications of the disorder and why it manifests the way it does in affected individuals. Understanding this mechanism is crucial for genetic counseling and understanding the risks associated with cystic fibrosis in families.