This volume is an expansion on the known treatment model of IEMs, one that establishes an innovative pathway approach and provides a new authority on this family of disease. Alongside the standard cadre of molecular and clinical underpinnings, this book includes coverage of newborn screening and an overarching treatment of IEMs as complex diseases.

Although neonatal screening was begun only 20 years ago, and is consequently still in its early stages, it is already a classic example of efficient preventive pediatrics. At present, routine neonatal screening covering a satisfactory percentage of newborn babies is carried out in only a small part ofthe world. For some five diseases enough infants have been screened to give reasonably reliable information about the frequency of these diseases in various populations. Interesting differences are beginning to appear in popula tions of different ethnic and racial background. The medical importance of neonatal screening is especially obvious in metabolic diseases that are not too rare and for which effective treatment depends upon an early diagnosis, such as phenylketonuria, galactosemia, and - a more recent screening pro gram - hypothyroidism. About 1 of 4000 newborns is affected with hypothyroidism and can receive timely substitution with thyroid hormone. Of 34.5 million babies tested for phenylketonuria, 3000 cases have been diagnosed in time to prevent mental retardation by means of dietary therapy.

Although neonatal screening was begun only 20 years ago, and is consequently still in its early stages, it is already a classic example of efficient preventive pediatrics. At present, routine neonatal screening covering a satisfactory percentage of newborn babies is carried out in only a small part ofthe world. For some five diseases enough infants have been screened to give reasonably reliable information about the frequency of these diseases in various populations. Interesting differences are beginning to appear in popula tions of different ethnic and racial background. The medical importance of neonatal screening is especially obvious in metabolic diseases that are not too rare and for which effective treatment depends upon an early diagnosis, such as phenylketonuria, galactosemia, and - a more recent screening pro gram - hypothyroidism. About 1 of 4000 newborns is affected with hypothyroidism and can receive timely substitution with thyroid hormone. Of 34.5 million babies tested for phenylketonuria, 3000 cases have been diagnosed in time to prevent mental retardation by means of dietary therapy.

Ju ̈ rgen G. Backhaus 1 Johann Heinrich Gottlob (von) Justi was born in 1702 in Bru ̈ cken in Prussia (county of Sangerhausen), studied law and cameral sciences in Wittenberg and Jena, yet had to leave the university, entered the Prussian military service, was captured during the Austrian war of succession by the Austrians but escaped to Leipzig (Saxony) where he studied mineral sciences. In 1750 he was called to a chair ‘‘Cameral Sciences and Rhetorics’’ at the new Theresian Academy of Knights in Vienna. There, he gave two important inaugural lectures which are the focal point of this book. In 1754, Justi was appointed a mineral counsellor in Gottingen ̈ (Hanover), and lectured at the Saxonian University on both state sciences and natural sciences. In 1762, Frederic II (the Great) of Prussia appointed him Prussian captain (highest supervisory position) of mines and general supervisor of fiscal-mineral activities. In 1768 he was accused of embezzlement, and before he could prove his innocence, he died in 1771 as a prisoner in the (decaying) fortress of Ku ̈ strin. Due to his death, the case was never decided. But Frederic had obviously made his own decision. When he appointed Justi, the appointee pointed out that he was suffering from weak eye sight and could not readily check the bookkeeping. Frederic replied: You may have weak eyes but you have a bright mind. I shall put two eyes by your side.

This manual deals specifically with laboratory approaches to diagnosing inborn errors of metabolism. The key feature is that each chapter is sufficiently detailed so that any individual can adopt the described method into their own respective laboratory.