Facts About Cystic
What is Cystic
Cystic Fibrosis (CF) is the most common fatal genetic disease among
Caucasians. It affects many organ systems of the
body, primarily the respiratory and digestive systems.
People with CF produce abnormally thick mucous which causes obstruction
of the airways along with frequent infections.
Repeated infections leads to permanent lung damage and eventually causes
death from progressive airway obstruction.
In the digestive system, thick mucous secretions prevent pancreatic
enzymes from reaching the small intestines where
they are needed to digest food. This can cause malabsorption of nutrients
and thus some children with CF appear small
in stature and can suffer malnutrition. If untreated, malnutrition can
result in serious consequences despite the large amount
of food eaten.
The need for long-term and often expensive therapy results because there
are many other complications that can occur as
the disease progresses.
The incidence of CF is approximately 1 in 2000 births. The average life
expectancy is 35 years although there are many
people with CF now in their 30's and 40's. Not so long ago, children
with CF were not expected to reach their teens.
As better methods of treating CF are discovered, life expectancy improves
and many recent CF births are expected to
survive into their 40's or longer.
What Causes CF?
CF is knovvn as a recessive genetic disease which means that both parents
must be carriers to have a child affected with
CF. A carrier does not have CF but does carry one CF gene. At the time
of conception, a child inherits one set of genes
from each parent, to have CF. If only one parent carries the CF gene,
the children may be carriers but will not have CF.
When both parents are carriers, the odds are one-in-four that a child
will have CF. There is a two-in-four chance a child
will be a carrier, and a one-in-four chance a child will neither be
a carrier nor have CF.
The defective gene responsible for CF is called CFTR, or Cystic Fibrosis
Transmembrane Conductance Regulator. The
most common defect is known as Δ F508 (delta 508).
This defect is present in 70% of people with CF although many
other mutations (well over 1200) have been identified.
Is There a Test to Detect CF
Yes. Recent advances in gene research and the identification of the
CF gene makes it possible to diagnose CF carriers.
This involves a blood test which is sent to a specialized laboratory
and analyzed for the 16 most common CF gene
Although there are well over 1200 mutations identified, the most common
is Ð F508 which is found in approximately 96%
of the "carrier" population. No other mutation is found in
more than 4% of the 'carrier' population with most found in under
1% of the "carrier" population.
The test has a high degree of accuracy but is not 100% reliable.
It is usually quite expensive but some insurance
companies cover the cost so it is best to check with your insurance
carrier before proceeding. The test is not
recommended as a general screening test but is usually reserved for
families with a history of CF based on physician
It is also possible to detect the presence of CF in an unborn child,
but this is generally reserved for cases in which both
parents are known carriers. This, too, is done in conjunction with genetic
counseling and physician recommendation.
What are Some Early Symptoms
CF has been called "the great masquerader" because its symptoms
can be similar to other disorders such as asthma. The
type and severity of symptoms often vary from person to person as does
the age when they first appear. Some early
• excessively salty sweat
• frequent or persistent cough
• frequent or persistent respiratory infections
• large, loose, clay-colored greasy stools
• failure to thrive or delayed growth
• large appetite or lack of appetite
About 10% of CF infants have what is called a meconiumileus or intestinal
blockage at birth or shortly after birth. In
young children, the presence of nasal polyps can also alert the physician
that CF may be present.
People suspected of having CF are given a "sweat test" which
measures the salt content of sweat and is almost 100%
effective in diagnosing CF. The "sweat test" is a simple,
painless, non-invasive procedure.
Why Do CF Symptoms Vary in Severity?
Just as every person is different, CF can affect each person differently.
Some patients may have very few symptoms
and may not be diagnosed until their pre-teens or older. Others develop
symptoms and complications early in life and
experience progressive deterioration in health.
The reasons for the differences in severity are not always
known but may be related to such things as the genetic defect
itself, age at diagnosis, treatment compliance, inattention to nutritional
needs as well as other genetic influences such as
the person's immune response.
How is CF Treated?
At present there is no cure for CF and treatment is aimed at treating
the symptoms and preventing complications.
Current treatments include strict attention to growth and nutritional
well being. This is done by assessing the degree of
malabsorption, attending to growth curves, using pancreatic enzymes
to aid digestion, and using nutritional supplements
along with a well-rounded high calorie diet.
Respiratory therapy is of great importance to help clear secretions
from the airways, prevent infection, and decrease
lung damage. This includes manual CPT (chest percussion therapy) and
mechanical devices such as nebulizers,
percussors, flutter valves, and percussion vests to loosen secretions.
In conjunction with this, medications
(such as pulmozyme) to thin secretions and dilate the bronchi are used
in an effort to loosen secretions and ease
CF researchers are investigating ways to replace the defective gene
in the lungs and ultimately find a cure. Although
the human gene therapy research is encouraging, the hope for a cure
or long term beneficial treatment is probably many
Currently the key to long-term survival in CF is the use of aggressive
treatment of both nutritional deficiencies and
bacterial infections. This is an ongoing process even when things are
going well. The emphasis is on maintaining optimal
health and preventing complications.
Myths, Misconceptions, and General
CF is not contagious. The only way to "get" CF is to be born
CF does not affect mental function or intelligence, and children with
CF do not have to "live in a bubble" or be treated
Although prone to lung infections, people with CF should be encouraged
to live a so-called normal life attending school
and socializing with friends, etc. General precautions should be taken
to avoid prolonged exposure to people who have
colds, the flu, or other infections.
Psycho-social development is another important aspect of living with
CF. People with CF, especially children, should be
encouraged to be as independent as possible, self-disciplined, and knowledgeable
about the disease.