“Crude” form of the disease

Dr. Lara Bilodeau Pulmonologist

Quebec University Institute of Cardiology and Pulmonology (Laval Hospital)

Quebec (Quebec) Canada

“CRUDE” FORM OF THE DISEASE

Q: I am now 59 years old and was diagnosed with cystic fibrosis at the age of 52. I was then told that I had a so-called “crude” form of the disease. Since then, I have received regular follow-ups from my cystic fibrosis clinic, and my respiratory capacity has been relatively stable although it has been declining for seven years. I can't find anything in the scientific literature about this form of the disease. Can you tell me more about it?

R : Cystic fibrosis is a complex disease, whose evolution and clinical manifestations vary greatly from one person to another. This variability is in part due to genetic factors. The majority of people with cystic fibrosis have a “classic” form of the disease, which occurs early in life by digestive problems (diarrhea, malnutrition, growth retardation) and respiratory problems (cough, secretions, frequent infections). The crude forms of cystic fibrosis correspond to milder forms of the disease.

Cystic fibrosis occurs when a person carries two mutations in the gene that causes the disease (a gene called CFTR). The term mutation means that the gene is changed and, as a result, faulty. Some mutations are considered to be mild because they produce a relatively functional gene. People with a crude form of cystic fibrosis have at least one mild mutation. They do not have all the classic symptoms of the disease. In general, they do not have pancreatic insufficiency, which means that their pancreas normally secretes the enzymes necessary for digesting food. They have no nutritional problems and can easily maintain a healthy weight. On the respiratory side, the symptoms are mild or sometimes even absent.

Unlike the classical forms of cystic fibrosis, which are usually detected in the first years of life, the crude forms are often diagnosed late. It is not uncommon to discover them only in adulthood. They are associated with a favorable evolution and a good survival prognosis.

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