CF Diagnosis

Question

My son suffers from CF and my daughter is the carrier of one CF pat. allele with the F508del mutation. A test has shown that my daughter´s sweat has 25mmol/l of chlorides. My son was tested because of the aforementioned salinity. To me, the soles of my daughter´s feet and her palms seem as salty as my son´s (sometimes even saltier). This happens even shortly after I give my children a bath. Is it possible that the sweat test result wasn´t accurate and the genetics laboratory didn´t find the other mutation and my daughter is also ill? Should I apply for another sweat test?

Answer

Hello,

This is a very delicate problem. However, judging by your words I think your daughter is only a carrier of the gene that can cause CF.

I´m sure that in your son's case you know both mutations of the CF gene as well as the chloride concentration in his sweat. I suppose that your daughter has also undergone proper testing in the same CF centre as your son. Does she have any problems like failure to thrive, stomach ache, stool problems, frequent airway infections etc.? If she doesn´t have any problems and has been tested in a CF centre which deals with this disease in a comprehensive way – and where your son is also monitored – there is no reason not to believe the results and worry that your daughter might suffer from the same disease as your son.

I understand your concerns and think it might be useful to arrange an appointment with a doctor – a geneticist who would rule out CF in your daughter, or discuss the matter with the CF specialist who treats your son.
Dr. J. Brázová

22.11.2011