|
How do people get cystic fibrosis?
Cystic fibrosis (CF) is a genetic disease. That means people inherit it from their parents through genes.
The defective gene that is responsible for causing cystic fibrosis is on chromosome 7. To have cystic
fibrosis, a person must inherit two copies of the defective CF gene—one copy from each parent. If both parents are carriers
of the CF gene (i.e., they each have one copy of the defective gene), their child will have a 25% chance of inheriting both
defective copies and having cystic fibrosis, a 50% chance of inheriting one defective copy and being a carrier, and a 25%
chance of not having CF or carrying the gene.
|
|
What are the symptoms of CF?
Approximately 30,000 people in the United States have cystic fibrosis. An additional ten million more—or
about one in every 31 Americans—are carriers of the defective CF gene, but do not have the disease. The disease is most
common in Caucasians, but it can affect all races. The severity of cystic fibrosis symptoms is different
from person to person. The most common symptoms are:
- Very salty-tasting skin
- Persistent coughing, at times with phlegm
- Frequent lung infections, like pneumonia or bronchitis
- Wheezing or shortness of breath
- Poor growth/weight gain in spite of a good appetite
- Frequent greasy, bulky stools or diificulty in bowel movements
- Small, fleshy growths in the nose called nasal polyps
Sometimes people are told that they have asthma or chronic bronchitis when they really have cystic fibrosis. New
research shows that the severity of CF symptoms is partly based on the types of CF gene mutations (defects). Scientists have
found more than 1,500 different mutations of the CF gene.
|
|
How is CF diagnosed?
Most people are diagnosed with CF at birth or before the age of 2. A doctor who sees the symptoms will
order either a sweat test or a genetic test to confirm the diagnosis.
A sweat test is the most common test used to diagnose cystic fibrosis. A small electrode is placed
on the skin (usually on the arm) to stimulate the sweat glands. Sweat is then collected and the amount of chloride, a component
of salt in the sweat, is measured. A high level of chloride—a score of more than 60 mmol/L (a measure of concentration)—means
that the person has cystic fibrosis. Scores between 40 mmol/L and 60 mmol/L are considered to be on the borderline and need
to be looked at on a case-by-case basis. Scores of less than 40 mmol/L are considered negative for CF.
In a genetic test, a blood sample or cells from the inside of the cheek is taken and sent
to a laboratory to see if any of the various mutations of the CF gene are found. A genetic test is often used if the results
from a sweat test are unclear.
|
|
|
|
How does CF affect the lungs?
Scientists have many different ideas about what goes wrong in the lungs of a person with cystic fibrosis,
but it all begins with defective CF genes. Normally, the healthy CF gene makes a protein—known as CFTR (Cystic Fibrosis
conductance Transmembrane Regulator)—that is found in the cells that line various organs, like the lungs and the pancreas.
This protein controls the movement of electrically charged particles, like chloride and sodium (components of salt) in and
out of these cells. When the protein is defective, as in cystic fibrosis, the salt balance in the body is disturbed. Because
there is too little salt and water on the outside of the cells, the thin layer of mucus that helps keep the lungs free of
germs becomes very thick and difficult to move. And because it is so hard to cough out, this mucus will clog the airways and
lead to infections that damage lungs.
|
|
Is CF fatal?
Currently, there is no cure for cystic fibrosis. However, specialized medical care, aggressive drug
treatments, and therapies along with proper CF nutrition, can lengthen and improve the quality of life for those with CF.
|
|
What is the life expectancy for people who have CF (in the United States)?
There is no way to accurately predict how long people with cystic fibrosis will live, as many different factors
may affect a person’s health. Severity of disease and time of diagnosis are two such factors. Many people have a mild
case of CF, while others can have moderate or severe cases. In addition, some adults with cystic fibrosis have only recently
begun to use new treatments, while an infant diagnosed at birth will have the advantages of starting specialized treatments
that were not available even a decade ago.
Using data from the CF Foundation Patient Registry more than 40 percent of all people with CF in this
country are 18 years or older. In 2005, the predicted median age of survival rose to 36.5 years,
up from 32 in 2000. The predicted median age of survival is the age by which half of the current CF Patient Registry population
would be expected to survive, given the ages of the patients in the registry and the distribution of deaths in 2005.
The steady rise of the median predicted age of survival suggests how improvements in treatment are advancing
the lives for those with CF. In 1955, children with CF were not expected to live even to first grade.
|
|
What is 65 Roses?
65 roses is what some children with CF call the disease. The pronunciations
of Cystic Fibrosis and 65 roses are very similar.
|
|
|
|
|
What about gene therapy? Is it a treatment for people with CF?
When scientists found the most common gene that causes CF in 1989, there was much excitement
about the possibility of developing gene therapy. Gene therapy is the process by which healthy genes are delivered into cells
and tissues of the body using such “vehicles” as a specially engineered virus. Researchers need to add enough
healthy genes to override the effects of the defective ones. If it is successfully done, gene therapy has the potential of
curing cystic fibrosis as it addresses the root cause of the disease (the faulty CF gene) and not merely the symptoms.
Scientists are currently exploring the use of gene therapy for many diseases but
have had little success. That is because it has been very hard to find a safe and reliable way to deliver healthy genes into
the cells and tissues of the body. For this reason, we cannot predict when and if gene therapy will become available as a
treatment. Gene therapy, like any other medical research, must be safe and effective before it can be used as a treatment.
Research is ongoing in both the clinic and the laboratory.
|
What is a PFT and is it routine for those living with CF to have it done?
PFT stands for Pulmonary Function Test, which is used to measure your breathing behavior.
The purpose of the PFT is to help your doctor determine the best type of treatment for you. It is common to have a PFT done
at each clinic visit, which is usually every 3 months or sooner depending on your condition.
|
What is The Vest?
The Vest™ is
designed to perform chest physiotherapy on CF patients. The system uses a technology called high-frequency chest wall oscillation.
It has an inflatable vest connected by tubes to a generator. During therapy, the vest inflates and deflates rapidly, applying
gentle pressure to the chest wall. This works to loosen and thin mucus and to move it toward the larger airways, where it
can be cleared by coughing or suctioning.
|
What is a nebulizer?
A nebulizer is a machine that is used to change a liquid medication into a mist for
easy inhalation. The liquid is changes into mist with the use of pressurized air generated by the nebulizer.
|
What is Hypertonic Saline?
Hypertonic Saline is similar to ocean water. It thins mucus in the lungs; helps eliminate
irritants that affect the nose and produce mucus, swelling, sneezing & itching; and shrinks swollen membranes by osmosis.
It is used to reduce the need for antihistamines & antibiotics. It also improves the symptoms of nasal & sinus diseases.
|
