Annual Report on External Quality Assessment in Inborn Error of Metabolism in Korea (1999).

Two trials of external quality assessment for inborn error of metabolism was performed in 1999. In Trial Ⅰ, 6specimens for neonatal screening test were distributed to 56 laboratories with a response rate of 78.6％. Three specimens were distributed to 64 laboratories with 50 returns (78.1％) in Trial Ⅱ. All the control materials were sent as a filter paper form. Each laboratory replied the test result as the screening items they were doing as a routine test at the reception of the specimen among PKU screening, neonatal TSH, neonatal T4 (total, free), galactosemia screen, 17-OH progesterone, maple syrup urine disease (MDSU) screen, homocystinuria screen and histidinemia screen. the median, range, mean, SD, and CV were analyzed.ope