nTSH - neonatal thyroid stimulating hormone; nG6PD - neonatal glucose 6-phosphate dehydrogenase; nCAH - neonatal congenital adrenal hyperplasia; n17-OHP - neonatal 17-hydroxyprogesterone; nBIOT - neonatal biotinidase; nPKU - neonatal phenylketonuria; nIRT - neonatal immuno-reactive trypsinogen; nGAL - neonatal total galactose. Here, BTD is linked to phenylketonuria.