[Inborn errors of metabolism (IEM) in adults. A new challenge to internal medicine]

Improvements in screening programs, diagnostic tests and therapeutic interventions in inborn errors of metabolism (IEM) have led to increasing and prolonged patient survival and improved prognosis of affected subjects. Today, in Germany about 200 patients with IEM survive per year into adulthood. They need specialized adult care. However, adult-oriented care is poor or absent in IEM, because traditionally, no specific adult service exists for this subspecialty and adult patients with IEM are a relatively new phenomenon. Part 1 of this overview deals with the diagnostic procedures of IEM in infancy, the principles of therapy in childhood, and the problems of transition/transfer of patients from pediatric to adult-oriented care. In part 2 the necessities of treatment in adults with the currently most important IEM are reported, which are mainly phenylketonuria and lysosomal storage diseases and less frequently glycogen storage disease type I, galactosemia, urea cycle disorders, and homocystinuria.