AB017. The extended newborn screening by tandem mass in Taiwan—results from two national newborn screening centers: Taipei Institute of Pathology & Chinese Foundation of Health

Abstract: Since 2001, tandem mass spectrometry was introduced for newborn screening by two Taiwan national newborn screening centers: Taipei Institute of Pathology and Chinese Foundation of Health, in Taiwan, respectively. A total of 24 metabolic disorders, including 6 amino acidopathies, 8 organic acid disorders and 9 fatty acid disorders, etc., were screened and the newborns with positive screening result were referred to Taipei Veterans General Hospital for confirmatory diagnosis. Until Dec 2014, a total of 1,391,583 newborns have been screened by these two newborn screening centers. The overall incidence of inborn errors of metabolism identified by tandem mass was approximately 1/6,000. The most common inborn errors were defects of phenylalanine metabolism (phenylketonuria: 1/60,000; 6-pyruvoyltertrahydropterin synthase (PTPS): 1/110,000). Maple syrup urine disease was the second most common amino acidopathy (1/100,000) and, significantly, most MSUD patients (75%) belonged to the Austronesian aboriginal tribes of southern Taiwan. The most frequently detected organic acid disorder was 3-methylcrotonyl-CoA carboxylase deficiency (1/35,000). Glutaric aciduria type 1 and methylmalonic academia were the second most common organic acid disorders (1/100,000 for each disease). The incidence of fatty acid disorder is relatively less than most western countries. Out of them, carnitine transport defect was the most common fatty acid disease (1/100,000). In this report we will present this large population study of tandem mass newborn screening in Chinese population.

Keywords: Tandem mass spectrometry; newborn screening; metabolic disorders; inborn errors