Can the diagnosis be taken back?

Question

Dear expert team,
you have already helped me once. Many thanks for that!! In my little son (now nearly 7 months old) CF has been diagnosed via the Newborn Screening. According to the genetic analysis he has two times F508-mutation. He has that with the pancreas and nothing else. He has never had cough until now and no rhinitis and nothing.
At the time of the sweat test (when he was 6 weeks old), his hands tasted salty. He has had many stools (nearly 10 times a day, I do exclusively breast-feeding, even upto now) but never voluminous, stinky or fatty. The stools are only looking like this since he takes the Kreon. Isn't that funny? In addition, he has since then only every 7-10 days stool. Because of that I am told to give only half of a spoon before the breast-feeding. Since birth he did gain weight very well.
His hands do not taste salty anymore, is it possible, that he has not CF? And what do you advice concerning the Kreon? Probably he does not need it at all? I am very confused right now, because I could not make a sense of it at the last visit at the CF center.
Many thanks in advance....

Answer

Hello,
you ask, if probably it could be once the case that the diagnosis of CF can or has to be taken back. In general, this is possible, if the diagnosis was done on the result of a sweat test and this test has been performed wrongly. In your child, a genetic testing had been performed and the mutation delta F508 had been detected twice. In case the sample has not been alternated wrongly, it is extremely unlikely that the result is wrong.
Because of the Kreon administration it should be clarified, if a measurement of the stool elastase I had been done before starting it. It is however certain with a probability of nearly 100% that patients with a homozygous state for delta F508 have already at birth a hypofunction of the pancreas. Nevertheless this should be secured by a laboratory investigation. In case there is a hypofunction of the pancreas in your child, then the child needs Kreon at a dosage of about 2000 IE lipase per gram nutritional fat. In case the stools go on being very frequent and fluid in spite of right dosage, a children's gastroenterologist has to search for other causes. With all the problems however it is important, that growth and gaining of weight of your child are normal.
Yours sincerely

22.06.2009