Mucoviscidosis is caused by a defect in the genetic material. Human genetic information (DNA) is divided into 46 chromosome pairs. Scientists name the individual sections of a chromosome genes. In mucoviscidosis, the so-called CFTR gene (Cystic fibrosis transmembrane conductance regulator) on chromosome 7 is damaged. Only when a person inherits both defective genes, will they fall ill. Biologists call this inheritance autosomal recessive.
Genes control the correct assembly of proteins in the organism. In the case of mucoviscidosis, a protein is incorrectly assembled, forming a non-functional chloride channel. Normally, chloride particles (salts) are transported through chloride channels, which keeps the body secretions liquid. This is exactly what doesn't work, making the liquids much too viscous. As a result of this disorder, the sweat of affected persons is much saltier than in healthy people.
In mucoviscidosis, the gland cells produce very thick mucus - with serious consequences: