CF

Question

My eleven-month-old son had a test carried out when he was three months old. The result showed that he has 74 mmol/l of chloride in his sweat. He weighs almost 12 kilos and so far he hasn´t been ill except cankers in his mouth. A genetics test confirmed that he has 2 CF-typical genes. I would like to know if CF can break out later in his life or if there is a possibility of a milder form of the disease. I would also like to know what the milder form will mean for us as a family, but, above all, for our son.

Answer

Hello,
We can answer your questions only sufficiently if we know which CF gene mutations your son has. There are two mutation groups. Within the first group so-called “serious mutations” (class I-III) which are usually connected with insufficient external pancreatic secretion and patient´s failure to thrive. Within the second group (class IV-V) mutations are usually associated with a sufficient function of the pancreas and also airway symptoms are milder. If we don´t know exactly which mutations your son has, we won´t be able to comment on his illness form or what it means for all of you.
However, in general, it is important to stress that the genotype of a certain patient (his underlying CFTR-mutations) is not suitable for making an individual prognosis, as the individual prognosis of a CF patient does not only depend on the underlying mutations but also on other genetic and environmental factors, especially on the initiated therapy and its adherence to it. From the above, it becomes clear, that apart from the “classical” clinical picture of CF with early failure to thrive, fatty stools and lung disease, there are many other pictures possible, a later onset or a milder course with sufficiency of the pancreas and milder lung disease due to underlying mutations and other factors. Even onset of symptoms only in adulthood and minmal symptoms do occur and are named “CFTR-related disorders”. But even if the underlying mutations would speak for a rather "classical type" of disease, early diagnosed children could be free of symptoms (mostly free of pulmonary symptoms) for quite a long time. It is most important that you are monitored at a specialzed CF-center who monitor and treat the function of the pancreas and the lung disease.

Dr. V. Vavrova and Dr. D. d'Alquen

22.11.2011