Pediatria pre prax 1/2016

Is a negative newborn screening test for cystic fibrosis sufficient to rule out the diagnosis?

We review the case of 10-month old child with a negative result of newborn screening. The child in infancy age developed serious symptoms of food allergy. The metabolic imbalance associated with hypochloremia, hypokalemia and hyponatremia us led to suspicion of cystic fibrosis. Although the chloride sweat test was negative we continued diagnosis. Genetic examination confirmed mutation in which the chloride sweat test may be negative.

Keywords: newborn screening, cystic fibrosis, food allergy, chloride sweat test