health

Cystic fibrosis is caused by a mutation in the CFTR gene located
on chromosome 7. The gene itself was first identified in 1989.
A child must inherit the defective gene from both parents
in order to develop CF. If either parent has a normal CFTR gene,
the child may be a carrier for the disease but will not have
any symptoms of cystic fibrosis. There are over 900 different
known mutations of the CFTR gene. There are an estimated 10
million carriers of the defective gene in the United States,
or almost one in every thirty-one people. If two carriers marry,
they have a 25 percent chance of having a child with
cystic fibrosis, and a 50 percent chance of having a child who
will be a carrier of the defective CFTR gene.
Some mutations of the CFTR gene cause more severe symptoms
than others or may affect different body systems differently.
In addition, the symptoms of CF vary somewhat with age.
In newborns, the intestines may be blocked by meconium
(a blackish-green stool that most babies pass in the first few
days after birth). These children may also have such symptoms as failure
to grow; bulky and greasy stools; and frequent respiratory infections.

In older children and young adults, symptoms of CF may include:

• An extremely salty taste to the skin.
  
• Constipation or blockage of the bowels.
  
• Frequent episodes of heartburn or indigestion.
• Smelly, greasy, or clay-colored stools.
  
• Coughing or wheezing.
  
• Frequent chest infections with bronchitis or pneumonia.
  
• Clubbing (swelling of the tips) of the fingers and toes.
  Failure to gain weight at a normal rate. Girls may have delayed
  puberty.

Some complications of CF that occur in some patients include liver
damage; polyps (tissue growths) in the nose caused by recurrent sinus
infections; frequent headaches; pain in the abdomen; and diabetes
resulting from damage to the pancreas.