SCREENING FOR METABOLIC DISORDERS IN CRITICALLY ILL NEWBORNS USING TANDEM MASS SPECTROMETRY

Abstract

Objectives: To estimate the incidence of inborn errors of metabolism among critically ill neonates using Tandem Mass Spectrometry (TMS). To define a range of amino acid (AA) and acyl Carnitine (AC) levels in critically ill neonates for improvement of interpretation of Newborn screening (NBS) suspicious results. Methods: Filter-paper blood spots were collected from 486 critically ill neonates over a period of 6 months. AA and AC were assayed in each sample. Positive cases had been treated and followed up once the diagnosis had been verified. Results: 11(2.3%) out of 486 patients were positive for IEM. Six disorders were detected during screening; Maple syrup urine disease (MSUD), 5 patients (45.5%); Non-Ketotic Hyperglycinemia (NKH), 2 patients (18.2%); Tyrosinemia type 1 (Tyr-1), 1 patient (9%); Methylmalonic acidemia (MMA), 1 patient (9%); Isovaleric acidemia (IVA), 1 patient (9%); Glutaric aciduria type 1 (GA-1), 1 patient (9%). Our study showed that AA and AC profile were significantly affected (P-value < 0.05) by gestational age, birth weight and nutritional status of any critically ill neonate. Conclusion: IEM should be considered in any critically ill neonate. MSUD is relatively a common metabolic disorder. For good interpretation of NBS results gestational age, birth weight and nutritional status of the patient should be considered in suspicious results.