Cystic fibrosis is an inherited genetic disorder that is characterized by the overproduction of bodily fluids such as sweat, mucus, and digestive juices. Cystic fibrosis occurs in a recessive manner and effects, on average, one in every three thousand newborns of European and Caucasian ancestry. The most common complications related to the disease are lung infections, malabsorption of nutrients (poor growth), and severe damage to the digestive system, pancreas, and other organs. The average life expectancy, for people affected by this condition, has increased significantly in the developed world today, although the cure for cystic fibrosis still remains unknown. Cystic fibrosis is a serious, chronic, and fatal disease. The severity of symptoms and the age at which they begin to manifest may vary from person to person, but the irreparable damage that cystic fibrosis causes to some vital organs, namely the lungs, will be the most probable cause of death for most individuals affected by this condition. Lung damage occurs because the overproduction of unusually sticky and thick mucus causes the airways to clog up. This makes the lungs prone to frequent bacterial infections including pneumonia. Recurrent infections not only cause symptoms such as coughing and shortness of breath, but over time can severely damage the lungs.

Two normally functioning copies of the CFTR gene commonly exist in the DNA of most people. For a person to be affected by cystic fibrosis both of these copies need to be malfunctioning. Meaning both are not producing the functional CFTR protein. Around one in thirty people have only one working copy of the CFTR gene, which makes them the carriers of the genetic mutation even though they are not affected by cystic fibrosis themselves. If two people who are carriers of the genetic mutation parent a child, that child will not necessarily be affected with cystic fibrosis. In fact the chances of that happening stand are only 25%. This is because it is necessary for the child to inherit the malfunctioning copies of the CFTR gene from both parents. Chances for the child to become a carrier are significantly higher at 50%. There are over 1500 mutations of the CFTR gene that can be responsible for the development of cystic fibrosis. However, in a great majority of cases, more than two-thirds, the culprit is the ΔF508 mutation. This genetic mutation is actually a deletion of three nucleotides on the protein chain at the 508th position and a loss of the amino acid called phenylalanine.

In many cases, the signs and symptoms of cystic fibrosis can be visible early on in the life of the affected individual. The first obvious symptom is the inability of a newborn baby to pass feces. This happens due to the clogging of the intestines by meconium. Meconium is the first stool of the newborn, which normally contains substances ingested during the baby’s stay inside the mother’s womb. The meconium is commonly made of mucus, bile, epithelial cells, amniotic fluid, and water. It is sticky and viscous. With individuals suffering from cystic fibrosis, meconium may become so thick that it blocks the intestines completely. This occurs with around 10% of newborns with cystic fibrosis. Other than this, there are certain tell-tale signs of cystic fibrosis that are shared by the majority of people suffering from the disease. The most common one is the salty skin. The levels of salt in the sweat of people with cystic fibrosis is higher than normal. Parents can often notice this when kissing their children. The list of respiratory and gastrointestinal signs and symptoms is quite long. Coughing followed by the production of thick and sticky mucus, shortness of breath, bacterial and fungal lung infections, sinus infections, stuffy nose, development of nasal polyps, pulmonary hypertension, and even coughing up blood are some of the possible symptoms of cystic fibrosis that manifest in the respiratory system.

Diagnosis There are several available methods of diagnosing cystic fibrosis. Prenatal testing is the first step towards calculating the risk for a child being born with cystic fibrosis. This type of testing is costly, so it is usually performed on only one parent to determine whether or not she or he is the carrier of the faulty CFTR gene. If the results show that the tested parent is the carrier, the other parent is tested also in order to determine the potential risk. Fetal testing, such as amniocentesis and chorionic villus sampling is also possible although it is associated with a high risk for the fetus. Other methods are used after birth and they involve screening of the newborn babies, blood tests genetic tests, and a sweat test. In many countries, the routine screening of the newly born babies is carried out. The screening involves a blood test in which the increased levels of immunoreactive trypsinogen (IRT) are looked for in the sample as a sign of cystic fibrosis.Some genetic tests are aimed precisely at discovering the defects in the genes that are associated with cystic fibrosis. These tests are usually performed when other methods require additional support for the accurate and definite diagnose to be set.