Sweat test 51 - Continued

Question

Dr Doudounakis,
Following your past suggestion the genetic testing for the 95% of mutations was concluded. The mutation G576A was detected (paternal), as well polymorphisms T854T, I148T and R668C. I remind you that the first sweat test was 51 and the second one 49. The IRT results at the time of birth ware negative (20). The child continues to eat with great difficulty, but we manage to have all the meals. For the last five months her height and weight are the same. She does not have any respiratory symptoms apart from 2 occasional infections. I am very worried. Is it possible for a carrier of a CF mutation to have borderline sweat test results?

Answer

Dear friend,
As we have discussed over the phone, you have a 18 months toddler with normal IRT (20) at birth. You did the first sweat test (51) because the baby did not gain weight. The genetic testing revealed that your husband has the mutation G576A & R668C while you carry the mutation I148T, without the polymorphism 3199del.
The child continues not to eat and gain weight, while its feces float sometimes.
The normal IRT, in conjuction with the genetic testing, are against the possibility of CF. However, there are 2 borderline sweat tests (51 & 49). As we discussed, you need to get in touch with your gastroenterologist in order to (a) perform a general testing of the pancreatic function and (b) explore the possibility of celiac disease. In any case you must visit our center to do another sweat test with the method of iontophoresis of pilocarpine.
Personally I do not think the child has CF, but we expect you at our centre for further checking.
Yours friendly,
Dr. Stavros Doudounakis

24.01.2013

14.01.13 This question referrs to the former question:
ecorn-cf.eu/index.php?id=65&tx_expertadvice_pi1%5Bshowitem%5D=2052&tx_expertadvice_pi1%5Bsearch%5D=

D. d'Alquen