Quick questions on Genetic disorders: cystic fibrosis, sickle cell, Huntington's: HSC Biology Module 8

Autosomal recessive pedigree (cystic fibrosis, sickle cell).

CFTR (cystic fibrosis transmembrane conductance regulator), chromosome 7. The most common mutation is $\Delta F508$, a three-base-pair deletion that removes phenylalanine at position 508 of the CFTR protein.

Autosomal recessive. Two unaffected carrier parents ($Cc \times Cc$) have a 25 percent chance of an affected child. Carrier frequency in Australians of Northern European ancestry is approximately 1 in 25.

CFTR is a chloride channel in the apical membrane of epithelial cells. Loss of function reduces chloride and water secretion onto epithelial surfaces, producing thick viscous mucus. The mucus obstructs:

Airway clearance physiotherapy, inhaled antibiotics, pancreatic enzyme replacement, high-calorie diet, and CFTR modulator drugs (e.g. ivacaftor for G551D, elexacaftor/tezacaftor/ivacaftor for $\Delta F508$). Lung transplant for end-stage disease.

"Describe" wants the cause and effects in order; "compare" wants the same features for each disorder; "evaluate" (e.g. genetic testing) wants a justified judgement weighing benefits, limitations and ethics.