Genetics of Cystic Fibrosis

Cystic Fibrosis, or CF, as it is often referred to, causes bodily disturbances in the cells with regard to salt and water transportation. This disturbance results in fluids with higher viscosity or thicker consistency. The mucous buildup interferes with the lungs and the digestive organs in that it is thick and clogs them up.

The organs that can fall prey to Cystic Fibrosis are the intestines, sinuses, pancreas, lungs, liver, and reproductive organs. Cystic Fibrosis is an inherited disorder and will affect one baby out of every 2500 in the U.S. The most common of its small victims are those of Hispanic and Caucasian descent. It is a rare case in that of a person of Asian or African descent.

In the early stages, the most common symptoms of Cystic Fibrosis are a slow growth, coughing, skin that has a salty taste to it, an increased hunger, dyspnea, respiratory tract infections, bowel movements, foul-smelling, oily and bulky in character. If complicated there are advanced symptoms as well that include liver disease, infertility, diabetes, weight loss, and pancreatitis. Testing to determine Cystic Fibrosis is through testing of the fetal cells, sweat cells, or blood. Treatment of Cystic Fibrosis is aimed at their optimal level by means of medications, therapies, diet, and nutrition, as there is no cure.

Because cystic fibrosis is a genetic disorder it means that it is passed from one generation of parents to their children. During conception you get one gene from both of your parents. Out of the 22 pairs of genes that human beings possess, this gene is 7th in line on the chromosomal chart. The culprit gene is the cystic fibrosis transmembrane conductance regulator or the more simply, CFTR gene. Its job is to regulate the distribution of the salt and water in our body cells by the means of a protein. When this gene fails to make this protein, CF is the result. The exact cause of this defect is unknown as there are over 1200 ways that this gene has mutated to cause the above symptoms.

The inheritance of a person contracting Cystic Fibrosis is as follows:

~Abnormal genes from both parents will result in a diagnosis of Cystic Fibrosis.

~One abnormal and one normal gene from each parent result in a child who does not have Cystic Fibrosis. However, this child will carry a defective gene and may pass that gene to their own child.

~Normal genes from both parents will, of course, produce normal children without any sign of Cystic Fibrosis or being carriers of this condition.

Prenatal care is always highly important in pregnancy. However, genetic testing is unnecessary and not normally done unless the person knows that they are a carrier. Most often a person carries the CFTR gene and is not aware of it until after they have delivered their baby. When one parent knows that there is a family history of CF in the family it is important for both prospective parents to be tested to rule out both to be carriers.

RESOURCES

Genetics Home Reference: What is Cystic Fibrosis

Cystic Fibrosis Foundation: Carrier Testing for CF

National Human Genome Research Institute: Learning About Cystic Fibrosis