Outcome data from 15 years of cystic fibrosis newborn screening in a large UK region.

BACKGROUND: The West Midlands Newborn Bloodspot Screening Laboratory is one of 16 in the UK and serves two tertiary paediatric cystic fibrosis (CF) centres (Staffordshire Children's Hospital at Royal Stoke and Birmingham Children's Hospital). CF newborn bloodspot screening (NBS) in this region started in November 2006 prior to the UK national roll-out in 2007. It uses an immunoreactive trypsinogen (IRT)/DNA/IRT protocol. We report the outcomes from 15 years of CF screening.

METHODS: The West Midlands CF NBS outcomes from 1 November 2006 to 31 October 2021 were reviewed. Clinical data were also obtained for babies referred to the CF centres as 'CF suspected'.

RESULTS: 1 075 161 babies were screened, with 402 referred as 'CF suspected' and 205 identified as CF carriers. Of the 'CF suspected' babies, 268 were diagnosed with CF, 33 with CF screen positive, inconclusive diagnosis (CFSPID) and 17 as a CF carrier. Any CF-related diagnosis was excluded in 67. Outcome data were not available for 17, of whom 14 had died. Eighteen children with a negative CF NBS have subsequently been diagnosed with CF, 10 had meconium ileus and 8 were true 'affected not detected', presenting with respiratory symptoms or failure to thrive. This gives the West Midlands a CF birth prevalence of 1 in 4012 live births and the NBS protocol a sensitivity of 97.1% and a positive predictive value of 66.7%.

CONCLUSIONS: This large regional data set has excellent case ascertainment and demonstrates successful performance of the CF NBS protocol, with low numbers identified as CFSPID or CF carriers.