Question

Genetics of Cystic Fibrosis.

Hint:

Cystic fibrosis is inherited in an autosomal recessive pattern, meaning both parents must carry a copy of the defective CFTR gene for a child to develop the disease.

Answer 1

Cystic fibrosis (CF) is an autosomal recessive genetic disorder caused by mutations in the CFTR gene (Cystic Fibrosis Transmembrane Conductance Regulator), located on chromosome 7. The CFTR gene encodes a protein that regulates the movement of chloride ions across cell membranes, affecting the lungs, pancreas, liver, and intestines.
1. Inheritance:
- CF is inherited in an autosomal recessive manner, meaning a child must inherit one defective gene from each parent to develop the disease. Parents who are carriers (have one defective gene) do not show symptoms of CF but can pass the defective gene to their offspring.
2. Mutation:
- Over 2,000 different mutations in the CFTR gene have been identified, but the most common mutation is F508del (a deletion of three nucleotides resulting in the loss of phenylalanine at position 508 of the protein).
3. Pathophysiology:
- The CFTR protein dysfunction leads to thick, sticky mucus in various organs, causing blockages and damage, particularly in the lungs and digestive system.