Cystic Fibrosis Analysis

This essay has a total of 2360 words and 11 pages.

Cystic Fibrosis


About 1 out of 201 Caucasian people carries at least one of the fatal defective genes
that cause cystic fibrosis, CF, or mucoviscidosis (in Europe) although carriers don't show
any signs of the disease. Therefore, 10 million2 people carry the defective gene and
aren't aware of it. Consequently, it makes it one of the most common genetic defect in
the United States.


CF is a autosomal recessive gene. That means that it may, but doesn't always skip
generations. In order to get this disease, both parents must be carriers. If one parent
has CF and the other one is not a carrier than there is a 100% chance that their child
will be a carrier. If one parent has CF and the other is a carrier than the child has a
50% chance of having CF and a 50% chance of just being a carrier. If both parents are
carriers than their child will have a 25% of having CF, a 50% chance of being a carrier
and a 25% chance of not being affected. CF is common in both males and females, there is
not a specific sex that it is more common in.


How does a person know if they have CF? There are many symptoms to this deadly disease
including: salty tasting skin, constant coughing, large amounts of mucus, trouble gaining
weight, frequent greasy, foul smelling bowel, growths in the nose (nasal polyps) and
clubbed or enlarged fingertips and toe tips is another symptom. Now there are many tests
that can be done to find put if a person has CF.


One way which CF can be detected is to observe the symptoms. A person doesn't need to
have all the symptoms in order to have cystic fibrosis, but they usually show most of
them. Another way are different genetic testing. Doctors can now do genetic testing for
CF, but about 10 years ago they couldn't. In 1989, the location where the of the
defective gene on chromosome number 7 is was discovered by Francis S. Collins from
University of Michigan. Tests can now be taken to see if an unborn child is infected with
CF such tests are amniocentesis, chronic villus biopsy3 and a removal of cells from the
embryo during invitro.


Many years ago, New York4 had a heat wave, and the hospitals became overwhelmed with
dehydrated CF children. These children became dehydrated much quicker than children
without the disorder. Thus eventually resulting in the formation of the sweat test which
is now the standard test. Doctors place a pad or filter paper on a patients arm or back.
A chemical called Pilocarpine, makes a burst of electricity to produce more sweat. Then
the pad is wrapped in plastic and is sent to a lab to get analyzed. The doctors then
would look for a high chloride content in the sweat. Another test is a blood test that is
administered 3 days after a baby is born. It is called Immunoreactive Trypsinogen5 if
that comes back positive it is then double checked with a sweat test.


Furthermore CF causes the sweat glands to release about 5 times6 as much salt as a normal
person would. This is why the skin of a CF patients may taste salty. They don't sweat
more, but when they perspire more salt is excreted. This causes the person to dehydrate.


CF is a disorder that causes the body to produce larger amount of mucus than normal. In a
normal person, mucus in the lungs helps get rid of germs and bacteria in the air. In a CF
patients the lungs become covered with a sticky mucus that is hard to remove and promotes
infection from bacteria. Over time infections cause the lungs to become extremely weak,
therefore ending in respiratory failure.


Also CF affects the digestive tract. The overproduction of mucus causes the pancreatic
ducts to be clogged. Therefore preventing necessary enzymes to digest fats and proteins.
Without those enzymes CF patients can't gain weight. The undigested proteins and fats
pass right through the body creating smelly bowel. In some cases this malnutrition causes
people to die when they are only children. Also it is more common for people with cystic
fibrosis to develop digestive tract cancer7. High levels of the protein CFTR (which the
gene makes) are found in the digestive tissues. Doctors explain this increased risk of
cancer because CF induces change in the digestive tract organs that causes the cell
turnover. Patients with gastrointestinal tract problem should get examined for such
tumors.


Women with CF can have children, but it is not very common. Giving birth is a vigorous
process and puts the mother's health at risk. It may also be hard for a women to get
pregnant though because the mucus blocks the sperm from entering the uterus the to the
fallopian tubes. About 98% of men with CF are infertile8. Even though sperm are
produced, they can't get to the semen because the vas deferens is blocked. In some new
research, it has been thought that men who are sterile have a different form of CF that
doesn't involve the digestive system and the lungs.


There are now many drugs that are in the market and many more that are in development.
Treatments mainly depends on what organs are effected. The first new drug therapy in 30
years was approved by the Food and Drug Administration in December of 93'. It's a
mucus-thinning drug called PulmozymeŽ. PulmozymeŽ has reduced the number of respiratory
infections and improved lung function. There is also postural drainage or thumps. This
treatment is when the patient is hit on the back and chest with cupped hands to loosen the
mucus so it can be coughed up easier. There are many antibiotics that help treat lung
infections. Also medicated vapors are inhaled and open clogged airways. Since mucus in
the intestines causes the food not to get digested, there are enzyme supplements to help.
Those enzymes allow patients to go back to a normal diet. Due to the high concentration of
the enzymes the end result is deterioration of the pancreas leading to diabetes. With the
supplements CF patients can eat normal food.


There are now many studies that the medicine ibuprofen (Advil, Motrin IB, Nuprin) prevents
serious damage to lungs in children who have CF. The trials involved 85 patients between
the ages of 5 and 39 with FEV1 equal or greater than 60%9. In this study patients that
took ibuprofen had a slower rate of decline of FEV1. Patients that took it for 4 years
consistently had even better results and showed best in patients under the age of 13. The
dose of ibuprofen was selected between 50 and 100up/mL because the anti-neutrophil effects
of ibuprofen are only attained at these levels. There are some side effects, including
conjunctivitis (unknown reason) and epistaxi (due to the anti-platelet action in the
ibuprofen. Doctors say that it is not sure if stomach pains are due to the ibuprofen, but
to stay on the medicine and to take antacids with magnesium and aluminum and not those
containing calcium. In 1990 two teams of researchers were able to correct CF cells in a
petri dish10. The next huge step happened in 199311, when the first experimental dose of
gene therapy was administered to a human. These were milestones in finding a cure or a
preventive treatment. They were huge steps because it marked the first time that
scientists were able to test new technology in people with the disease. Also in October
of 93'12 scientists at the University of Iowa made another big step, they determined that
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