Cystic Fibrosis


Biology, Period 8


Cystic Fibrosis is a genetic disease that is simple recessive. This means that a child must have two abnormal copies of the gene, one from the mother and one from the father, to have cystic fibrosis. If both parents carry one abnormal copy of the gene, each child has a twenty-five percent chance of inheriting the disease. About thirty thousand children and adults have the disease, and one in every thirty-one Americans carries the abnormal gene. In the nineteen fifties, children with cystic fibrosis died in their early childhood, but today they are expected to live to their thirties due to medical treatment.


Cystic fibrosis is a chronic, progressive condition that affects the digestive and respiratory systems. The gene defect causes the body to produce abnormally thick mucus. The mucus clogs the lungs and leads to lung and sinus infections and difficulty breathing. The thick mucus also obstructs the ducts of the pancreas, which prevents digestive enzymes from reaching the intestines. Those with cystic fibrosis are unable to absorb much of the nutrients from food, so they have poor weight gain. Cystic fibrosis also makes the body produce a high amount of sodium and chloride in the sweat. This gives a very salty taste to the skin. The disease also causes reduced oxygen in the blood. People with cystic fibrosis can have a barrel shaped chest due to difficulty breathing.


People can find out if they have cystic fibrosis by taking a sweat test. It is a simple and painless process that measures the amount of salt in the sweat. High amounts of salt in the sweat could mean that person has cystic fibrosis. Patients can treat cystic fibrosis by cleaning mucus from the lungs everyday. Chest physical therapy is used to dislodge mucus from the lungs. There are also many drugs available to treat lung infection. There is even a drug that can thin out the mucus produced in the lungs.


Much research has been done to improve the lives of people with cystic fibrosis. Especially after scientists discovered the cystic fibrosis gene in 1989. Gene therapy, using normal genes to replace defective ones, has been the main focus of research. Trials have shown that the normal gene can be transferred into the cystic fibrosis airways, but not efficiently enough to be used. Some ways to insert genes that are still being tested are nasal drops, and compressing the DNA and hoping that it will enter the nucleus of cells. Progress in gene therapy is still continuing, but scientists are using their knowledge to develop other treatments.


The main goal of the Cystic Fibrosis Foundation is to find a cure for the disease. They perform clinical trials to test out new treatments. They also have research programs in top universities to increase awareness of cystic fibrosis.



Duchenne Muscular dystrophy is a sex-linked disorder. It only occurs in males, and symptoms are not seen until the boy is about ten years old. There is no way to detect Duchenne muscular dystrophy before birth. The symptoms of this disease include muscle weakening, especially in the limbs, and heart problems. It can be treated by physical therapy to reduce muscle tightening. Also, the boy may be put in a wheel chair if he cannot use his legs, and there are many support groups for children with muscular dystrophy. The main goal of the Muscular dystrophy association is to research to find a cure, especially because it is a fatal disease.