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GENETIC DISORDERS PROJECT
CYSTIC FIBROSIS
FANOURAKI MARIA
27137 CHARALAMPIDOU ALEXANDRA 27138
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CYSTIC FIBROSIS (CF)
What is CF?
CF is a genetic, inherited and non contagious
disorder characterized by the affection of the
bodys exocrine glands and airways, preventing
them from functioning properly. It is one of the
most common disorders in Caucasians (1 in 22 is a
carrier and 1 in 3300 is a CF patient).
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Genetics CF is a genetic disorder because it is
caused by mutations in the CFTR gene. This gene
(located on chromosome 7) encodes the CFTR
protein which is important for the proper
function of epithelium cells. A patient has 2
copies of the mutated gene (Mendelian autosomal
recessive inheritance). The most common mutation
is known as delta-508.

• The normal sequence of the CFTR gene.

Pict.1
ii) The delta-508 mutation
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How does CF affect the body?
CF sufferers produce an abnormal CFTR protein
that doesnt function properly and eventually
leads to the presence of high levels of salt in
patients sweat and the production of thick and
viscous secretions. This pathological condition
affects the respiratory, digestive and
reproductive system.
Pict.2 The CFTR protein
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How does CF affect the respiratory system?
CF affects both the lungs and the sinuses.
Patients suffering from CF produce thick, sticky
mucus in excess within their airways. This
secretions become impossible to be removed
normally from the respiratory system. Eventually
they block the small airways which then become
easily inflamed. As the disease progresses the
changes that take place in the respiratory system
lead to reduced ability of the lungs to transfer
oxygen to the blood and to all bodys tissues.

Pict.3 ? patients lung. Blue and green colors
show the airways, clogged by mucus.
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How does CF affect the digestive system?
In patients with CF the viscous mucus that is
produced from the epithelial cells, obstructs the
ducts of the pancreas, the gastrointestinal
tract, also the bile ducts and some of the
salivary glands. So, it is difficult for their
products to be secreted. Therefore, there is food
maldigestion and malabsorption.
Pict.4 The digestive system
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How does CF affect the reproductive system?
In males CF causes abnormal development of the
vas deferens and problems with sperm
transport. In females CF causes the production of
too thick cervical secretions.
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Symptoms

• Repeated sinus and respiratory infections
• Collapsed lung (pneumothorax)
• Chronic cough often accompanied by gagging,
  vomiting and disturbed sleep
• Coughing up blood (hemoptysis)
• Wheezing and breathing difficulty
• Nasal polyps (bumps inside the nose)
• Nasal congestion
• Abundant respiratory secretions
• Barrel-shaped chest
• Clubbed fingers and toes

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• Failure to thrive (a condition where a child
  doesnt gain weight or grow in height normally)
• Vitamin and mineral deficiency which may lead to
  night blindness, rickets, bleeding disorders and
  anemia
• Rectal prolapse (a condition where the lining of
  the large intestine protrudes through the anus)
• Stomach aches
• Meconium Ileus (a form of intestinal obstruction
  in newborns) may lead to perforation of the
  intestinal wall or a twisted intestine
• Bright or echogenic bowel (when they can see a
  Meconium Ileus in development in the uterus
• Chronic diarrhea

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• Frequent, greasy, bulky, foul-smelling stool
• Declining physical endurance
• Splenomegaly
• Delayed puberty
• Foul-smelling breath
• Insulin-dependent diabetes
• Cirrhosis
• Salty sweat and skin
• Dehydration
• Sterility in males-decreased fertility in females
• Heart failure

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Diagnosis

• Sweat testing It has been the most common method
  to diagnose CF for 40 years. The test reveals the
  amount of chloride in sweat. Elevated levels
  (more than 60 mmol/L) prove the existence of CF.
• Trypsinogen test It is a quite common test that
  measures the amount of an enzyme (trypsinogen) in
  the blood. High levels suggest CF.
• Chest X-Rays
• Lung function tests
• Fecal fat test It determines the amount of fat
  in the stools and dietary fat that is unabsorbed.

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Treatment

• Gene therapy ? normal CFTR gene is transferred
  into the patients cells living in the
  respiratory tract. The normal gene produces a
  functional CFTR protein.
• Antibiotics ?hey are used against infections.
• Aerosol sprays ?hey fight breathing problems.
• Pancreatic Enzyme Replacement Therapy (PERT)
  Capsules are taken with every meal or snack. They
  contain enzymes that are essential for food
  digestion.
• The flutter It is a device that clears the
  mucus which clog the patients airways.
• Nutritional support There is excessive need for
  vitamins, enzymes, proteins, fats and salt.

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and some interesting things about CF

• Most people ignore CF, although it is the most
  common genetic disorder in our race.
• Over 1000 mutations in the CFTR gene have been
  found to cause CF.
• The median survival is approximately 40 years,
  whereas in 1950s it was 8 years.