Pathology True about cystic fibrosis A The underlying defect in sodium channel function B The immune reactive trypsin (I) may be checked on the Guthrie card C In most cases the gene c defect is a loss of Valine at position 508 on chromosome 7 D A sweat test with a sodium content above 40 mmol/l is diagnos c 💡 Explanation True about cystic fibrosis ✓ Correct Answer: B. The immune reactive trypsin (I) may be checked on the Guthrie card