1.   Because of a genetic defect, the cells produce a defective signaling protein..

2.   In CF patients, defective CFTR protein causes a salt buildup, leading to an abnormally thick mucus, infection, inflammation and progressive lung damage.

3.   They know what their defective proteins look like, and how they behave in the cell.

4.   Work on these disorders might lead to treatments in which defective proteins would be replaced through gene therapy or managed through drugs.

5.   One major theory says this defective protein gets chopped into fragments, and one of those fragments is toxic to brain cells.

6.   The result, the researchers say, is defective proteins.

7.   Then the gene therapy involves knocking out the defective gene and blocking its ability to synthesise the defective protein which is toxic.