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
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.