Objective: To determine the genotype of patients attending the cystic fibrosis clinic at John Hunter Hospital, Newcastle, Australia.
Methodology: Seventy-five of the 76 patients attending the clinic over a 6 month period had blood collected for genetic analysis of 17 of the cystic fibrosis (CF) gene mutations.
Results: Sixty-one per cent of the patients were homozygous for the delta F508 mutation and all except one child had at least one delta F508 mutation.
Discussion: Nearly 80% of the CF genes were the delta F508 mutation. This prevalence suggests that the obligatory false negative rate of a newborn screening programme for CF based on a combination of immunoreactive trypsin and the delta F508 gene may be as low as 4-5%.