Abstract
BACKGROUND AND OBJECTIVE: Vietnam is the easternmost country on the Indochina Peninsula in Southeast Asia. With an estimated 90 million inhabitants as of 2013, it is the world’s 13th-most-populous country, and the eighth-most-populous Asian country. Congenital anomalies accounted about 22% of causes of deaths in children under-5 [2010]. The first service for IEMs was set up at the Northern referral center of Pediatrics-National Hospital of Pediatrics, Hanoi (NHP) in 2004 officially. The NHP in Hanoi provides services to the population of North Vietnam (~30 million people). The aim of this report is to highlight disease spectrum of tandem mass spectrometry (MS/MS) target disease in Vietnam. METHODS: A total of 2,405 high-risk cases with IEMs were studied at NHP during 10 years [2005-2014]. Dry blood and urine samples were analyzed using MS/MS (amino acid & acylcarnitine analysis) & GC/MS (organic acid anaysis) at Shimane University, Japan from 2005. Organic acids analysis for fresh urine samples was performed at NHP using GC/MS at NHP from 2010. Amino acid analysis for plasma samples were performed using HPLC at NHP from 2012. RESULTS: Oganic acidemia (OAs), amino acid disorders (AAs), urea cycle disorders (UCDs) and fatty acid oxidation disorders (FAOD) were identified in 235/2,405 cases (9.8%). A total of 118/235 patients (50.2%) were OAs with 12 different disorders: BKT (33 cases), PPA (21 cases), 5-oxoprolinuria (19 cases), MMA (14 cases), Glutaricaciduria type II (GA II) (11 cases), 3-methylglutaconic aciduria (4 cases), isovaleric academia (3 cases), multiple carboxylase deficiency (MCD) (2 cases), 3-methylcrotonylCoA carboxylase deficiency (2 cases). A total of 42/235 patients (17.9%) were amino acid disorders including 35 cases with MSUD, 7 cases with PKU and 1 case with tyrosinemia type 1. The 36/235 patients (15.3%) were UCDs including OTC deficiency (13 cases), citrulinemia type 1 (1 case) and argininosuccinic aciduria (1 case). 39/235 patients (16.6%) were FAOD including SCAD (3 cases), MCAD (3 cases), VLCAD (8 cases), LCAD (2 cases), CPT 2 (8 cases), CPT 1 (1 case) and primary carnitine deficiency (14 cases). Mortality rate was reduced from 50% in 2005 to 9% in 2014. CONCLUSIONS: Treatable conditions of IEMs were most common in Vietnamese patient identified using MS/MS. Expending newborn screening using MS/MS should be introduced to reduce mortality in Vietnamese children.