What causes CF?
CF is caused by a fault in the CFTR gene on chromosome 7; the gene produces a protein that regulates the movement of salt and water out of the body's cells. In individuals with CF, the gene produces a protein which does not function correctly. As a result, this creates thick, sticky mucus rather than thin, watery mucus, within the respiratory system (lungs particularly) and digestive system, along with very salty sweat. Changes in the CFTR gene can alter the CFTR protein, causing failure of chloride ion and water transport in and out of cells. This alters the salt and water balance on epithelial membranes (lungs and pancreas). F508del is the mutation
How is CF inherited?
Cystic Fibrosis is inherited when a child receives a faulty CFTR gene from each parent (the recessive gene). Those who inherit one normal and one faulty gene are considered CF carriers but are not affected by the disease.
Symptoms of CF
Depending on the severity of the disease, symptoms differ...
- Thick, sticky mucus which blocks the tubes that carry air into and out of the lungs
- A continuous cough that produces sputum
- Shortness of breath
- Inflamed nasal passages
- Continual lung infections (mucus accumulation provides a perfect environment for bacteria and infection) (pneumonia and bronchitis)
Thick mucus blocks tubes which transport digestive enzymes from the pancreas to the small intestine. As a result, the intestine are not able to fully absorb nutrients the body needs...
- Foul-smelling, greasy stools
- Little weight gain and poor growth
- Intestinal blockage
- Severe constipation
About 1000 new cases are diagnosed each year.
Over 75% of people with CF are diagnosed by age 2.
Over 30000 people in the United States are living with CF.
Today, the current life expectancy for CF patients who live past childhood is about 37 years old. Up until recent years, the life expectancy did not exceed the early 20's due to debilitating lung disease. Today, however, many CF patients are able to attend school and participate in day-to-day activities with today's medical advancements (medications to fight lung disease, mechanical chest therapy devices, and transplants).
Quality of Life
CF requires daily care, yet most patients are able to attend school and work. Patients must maintain frequent medical checkups, a healthy diet, avoiding smoking and tobacco use, washing hands regularly to prevent infection, doing chest therapy as doctor recommends. Also, many individuals with CF often have to be hospitalized due to frequent infections. CF patients' diets are often altered tremendously due to blockage in the pancreatic duct, meaning that digestive enzymes are not able to reach the small intensities to absorb key nutrients. As a result, a G tube of NG tube is often needed as a dietary supplement; patients, therefore, do not always have the ability to eat whatever they would like.
Patients with CF cannot be together-people with the disease hold dangerous bacteria that are contagious only to people with CF...normal individuals can fight off this bacteria (advised to stay 6 feet away from one another).
Long Term Prognosis + Ability to Thrive
Most children do not decline until early adulthood. They are able to attend school and participate in daily activities; many even finish college and find jobs. Lung disease, however, eventually worsens to where the patient is disabled and hospitalized. In today's time, the average lifespan is 37 years old due to recent advancements, treatments, and medications. Death, however, is usually caused by lung complications.
Prevalent in a Specific Population?
CF affects about one in 2,500 people of European ancestry--1 in 25 people of European background are a carrier of the disease. Cystic Fibrosis does not affect African Americans or individuals of Hispanic or Asian ancestry. Caucasians are at the highest risk of inherited CF, while Asian Americans are at the lowest.
- Sweat chloride test: usually tested in newborns and toddlers (high salt level in individual's sweat is the primary indicator of CF).
- Immunoreactice trypsinogen test: (standard test on newborns)-blood screening which shows gene mutations.
- Genetic test (swabbing).
- Lung function tests
- Testing for trypsin and chymotripsin in stool
- Fecal fat test
- Secretin stimulation test
- Measurement of pancreatic function
- Antibiotics which prevent lung and sinus infections (oral, intravenous, breathing treatments).
- Inhaled medications (open airways).
- Medications given through breathing treatments that break up mucus and make it easy to cough up DNAse enzyme.
- Lung transplant
- Oxygen therapy
- Chest physiotherapy
- Special diet (high in protein + calories)
- Pancreatic enzymes
- Vitamin supplements
- Ivacaftor (medication that thins mucus)