It is a lung disease. It is based on the CFTR gene’s errors (CFTR = Cystic Fibrosis Transmembrane Conductance Regulator). The genetic defects influence the salt balance and thus the conductivity of the cell membranes.
The lung damage that occurs in cystic fibrosis and the complications associated with it are particularly problematic. Thanks to intensive research, the mean life expectancy with cystic fibrosis has now increased significantly. Early diagnosis and new therapeutic approaches can also improve cystic fibrosis patients’ quality of life and life expectancy even further.
What are the symptoms of cystic fibrosis?
Due to the broken ion channel and the disturbed salt balance of the cells, sufferers with cystic fibrosis experience numerous typical complaints that affect different organs. However, many symptoms of cystic fibrosis resemble the symptoms that can occur with other diseases such as bronchitis, asthma, and celiac disease. Therefore, there can be misdiagnosis at the beginning.
Cystic fibrosis symptoms of the lungs
Those affected with cystic fibrosis often suffer from complaints in the respiratory tract due to the thick mucus. This includes
• persistent chronic cough,
• increased mucus production,
• wheezing breath sounds,
• Drumstick finger,
• chronic sinus infections and
• recurrent pneumonia.
• Dysfunction of the digestive tract
Mucus also affects the digestive system as it clogs the pancreas and liver and prevents digestive enzymes from entering the intestines. Cystic fibrosis symptoms can already be felt in babies. The first stool, the so-called meconium, often causes problems that can lead to intestinal obstruction (ileus).
• persistent diarrhea,
• foul-smelling stool,
• Underweight and
• Growth retardation
Cystic fibrosis cause: the CFTR gene
The CFTR gene responsible for cystic fibrosis has been known since 1989. It lies on chromosome 7 and serves as a blueprint for a transport channel through which chloride and bicarbonate ions are transported out of the mucous membrane cells.
In healthy people, the cells excrete chloride ions through this channel, combining sodium outside the cell to form common salt (sodium chloride, NaCl). To compensate for the increasing salt concentration outside the cell and to bring it into line with the attention in the cell, water flows out of the cells and thus moistens the mucous membranes.
In people with cystic fibrosis, the function of the ion channel is disturbed by errors in the CFTR gene. An acidic, water-poor environment is formed outside the cell. As a result, the mucus formed by the mucous membrane cells becomes viscous, clumps, and can only be removed with difficulty. As it progresses, it clogs the delicate branches of the bronchi in the lungs, the ducts of the pancreas, and the bile ducts. This ultimately leads to severe airways and digestive organs (intestines, pancreas, liver, kidneys).
The most common mutation in Germany is the so-called Phe508del mutation. As a result of the mutation, three base pairs are missing in the sequence of the CFTR gene and thus the amino acid phenylalanine at position 508 of the CFTR protein. As a result of this error, the protein cannot be folded correctly and is broken down before it even reaches the cell surface.