Medium chain acyl-CoA dehydrogenase deficiency (MCADD), which had been implicated in several cases of sudden infant death syndrome[7][8][9] was one of the first conditions targeted for inclusion. MCADD was the first condition added when the United Kingdom expanded their screening program from PKU only.[3] Population based studies in Germany, the United States and Australia put the combined incidence of fatty acid oxidation disorders at 1:9300 among Caucasians. The United States screens for all known fatty acid oxidation disorders, either as primary or secondary targets, while other countries screen for a subset of these.[10]