The definition of CFSPID (cystic fibrosis screen positive, inconclusive diagnosis) includes children with a positive neonatal screening, in whom cystic fibrosis cannot be unequivocally confirmed due to the following: the absence of symptoms of the disease; the presence of the CFTR gene mutation that is of, as yet, unknown clinical significance; and/or an abnormal sweat test result, but less than 60 mmol/L. The gene discussed is CFTR; the disease is cystic fibrosis.