Performance data from 2017 to 2018 [11] indicated that 92.7% of babies with a CHT positive screening result had an appointment with an appropriate clinical team initiated within three working days of sample receipt by the NBS laboratory, compared to 100% of babies with MSUD, GA1, IVA and MCADD and 99.1% of babies with PKU. This evidence concerns the gene SLC5A7 and phenylketonuria.