Rachel S Carling, Katy Hedgethorne, Anupam Chakrapani, Patricia L Hall, Nick Flynn, Toby Greenfield, Stuart J Moat, Joshua Ssali, Lynette Shakespeare, Nazia Taj, Teresa H Y Wu, Mark Anderson, Arunabha Ghosh, Hugh Lemonde, Germaine Pierre, Mark Sharrard, Sreevidya Sreekantam, James R Bonham
Since the UK commenced newborn screening for isovaleric acidemia in 2015, changes in prescribing have increased the incidence of false positive (FP) results due to pivaloylcarnitine. A review of screening results between 2015 and 2022 identified 24 true positive (TP) and 84 FP cases, with pivalate interference confirmed in 76/84. Initial C5 carnitine (C5C) did not discriminate between FP and TP with median (range) C5C of 2.9 (2.0-9.6) and 4.0 (1.8->70) µmol/L, respectively, and neither did Precision Newborn Screening via Collaborative Laboratory Integrated Reports (CLIR), which identified only 1/47 FP cases...
March 13, 2024: International Journal of Neonatal Screening