CFTR is a gene, or protein, that helps to produce mucus. Mucus cleans, lubricates, and protects many entry and exit points in the body, like the lungs and pancreas.
THE ROLE OF CFTR
The role of CFTR is to allow chloride ions, or salt, to exit the cells that produce mucus. When the salt leaves so does water to help thin the mucus. By allowing the passage of salt and water, CFTR helps keep the mucus from becoming overly thick and sticky.
HOW DOES CFTR CAUSE CF?
In Cystic Fibrosis, CFTR can't let salt out of the mucus producing cells. The decrease of salt going out also means a decrease of water coming in, thus the mcuus becomes thick and sticky. The thicker consistency barrs it from moving easily and clogs the entry and exit ways of the cell.
WHAT DOES THE MUCUS DO?
In the pancreas the clogged passageways of the cells prevent the secretion of enzymes that help digest your food, especially fat, which can lead to malnutrition.
Having the thicker mucus in the lungs may plug up the airways, which prevents good air exchange and intereferes with the removal of dust and bacteria which cause frequent, and sometimes life-threatening, lung infections.
Think of a gene as a sentence. A sentence is made of a long string of words, each one made of letters. A gene is exactly like that, except it's letters represent chemical letters called nucleotides. In a sentence you can rearrange the letters to change the meaning, the same principle goes for genes. By moving or deleting one or more of the letters a gene is changed, or mutated.
HOW IS CFTR MUTATED?
The gene defects in CF are called point mutations. This is because the gene is mutated only at on spot. The mutations, like the delta-F508, are caused by the loss of one letter in the CFTR gene. The loss of this letter changes the blueprint for how the gene is supposed to be made, this results in a gene that is made incorrectly and cannot function like it should.
CFTR?
The cause of the mutation in CFTR is not known. However, scientists feel that CFTR is developing and mutating so quickly, with so many different variations, that it's origin, and original cause of mutation may never be discovered. In that way, it is much like the AIDS virus. Every time it is introduced to a new treatment it mutates and changes it's chemical makeup so that it becomes resistant to the knew treatment. The wide scale of mutations makes it hard for science to keep up.