Question

Which of the following is not true of the Cystic Fibrosis?

a. CFTR deficiency leads to an increase of fluid that bathes the epithelial cells of the airways.
b. It is the most common ion channel disorder.
c. Gene responsible for CF was isolated in 1989
d. CF heterozycotes may be protected from cholera and typhoid fever.
e. 70% of the alleles responsible for CF contain the same genetic alteration, ΔF508

Answer 1

The statement that CFTR deficiency leads to an increase of fluid in the airways is incorrect; CFTR malfunction results in less water following osmotically and thick, sticky mucus in cystic fibrosis patients. The correct option is a. CFTR deficiency leads to an increase of fluid that bathes the epithelial cells of the airways.

Step-by-step explanation:

The correct answer to the question, "Which of the following is not true of Cystic Fibrosis (CF)?" is option a: CFTR deficiency leads to an increase of fluid that bathes the epithelial cells of the airways.

This statement is incorrect because the CFTR protein is responsible for transporting Cl- ions out of the cell and when this protein is malfunctioning, as it is in people with CF, there are fewer Cl- ions in the mucus, which leads to fewer water following osmotically, resulting in thick and sticky mucus rather than an increase of fluid.

Options b, c, d, and e are true. Cystic Fibrosis is indeed the most common ion channel disorder, the responsible gene was isolated in 1989, heterozygote carriers may exhibit some protection against cholera and typhoid fever due to the allele's presence, and 70% of CF alleles contain the ΔF508 genetic alteration. The correct option is a. CFTR deficiency leads to an increase of fluid that bathes the epithelial cells of the airways.