Garrin is a 7-year-old boy with cystic fibrosis. The disease is caused by a genetic defect on ...

Genes are the individual units of inheritance that transmit information from one generation to another. They are contained in DNA, which are in turn coupled with DNA-associated proteins to form chromatin. When chromatin condenses, chromosomes are formed, and it is on the seventh chromosome that the defective gene rests.

Chloride channels are integral, or transmembrane, ion channels. Ion channels function to
move ions that would otherwise be unable to cross the lipid bilayer.
create an electrical gradient for the function of excitable cells (i.e., nerve cells and muscle fibers) and for the function of secretory cells.
assist in the regulation of cellular osmotic pressure.
provide electrical gradients to speed the movement of ions across the membrane.

The retention of ions increases intracellular osmotic pressure as there are more ions in the cell in relation to the extracellular environment. As a result, water moves into the cell, leaving mucous secretions thick and viscous.