Somesh Kumar, Avinash Lomash, Bijo Varughese, Sourabh Bidhan, Sumaira Khalil, Sunil K. Polipalli, Seema Kapoor
Background: Children with high suspicion of IEM is a more effective screening strategy in a resource limited country like India. We present a prospective analysis of symptomatic children with red flag signs suggestive of IEM referred for analysis by LCMSMS. This study investigated the spectrum of IEM in symptomatic children over a period of 5 years (1st June 2010 to May 31st 2015).
Methods: A total of 3,250 symptomatic children for IEM were screened. Dried blood spots were collected and processed by MS/MS (API-2000 & 3200 Qtrap), using a non derivatized kit, analysed by R-4 Stork algorithm.
Results: A total of 3,250 children, 1,803 boys (56.34%), 1,397 girls (43.66%) with a median age of 20.8 months (range, 0.04-148.2 months) were screened. The 125 were diagnosed with an inborn error of metabolism, with a detection rate of 3.90%. Of these, 78 (62.40%) were males and 47 (38.60%) were females with a median age of 6.55 months. Clinical variation among the patients were unexplained encephalopathy, seizures, convulsions, delayed milestones with global developmental delay, persistent metabolic acidosis with increase anion GAP. The commonest group was amino acid disorders affecting 61 (48.8%) with phenylketonuria (n=5), hyperphenylalaninemia (n=4), maple syrup urine disease (n=8), hypermethioninemia (n=3), hyperglycemia (n=14), tyrosinemia (n=5), classic neonatal onset citrullinemia (n=4), 3 with hyperornithinemia, 10 with rasied alanine (as a secondary indicator), 3 with argininemia and 2 with remethylation defect. Organic acidemias 37 (29.60%) were methylmalonic academia (n=15), malonic aciduria (n=3), propionic aciduria (n=5), glutaric academia type I (n=5) and with 3-Methyl crotonyl-CoA carboxylase deficiency (n=9). Fatty acids disorders were seen in 27 (21.60%) children with medium-chain acyl-CoA dehydrogenase deficiency being the commonest (n=5), and very-long chain acyl-CoA dehydrogenase deficiency (n=2), carnitine palmitoyl-transferase Ia deficiency (n=12), carnitine palmitoyl-transferase II deficiency (n=8).
Conclusions: Mental retardation, delayed motor and language milestones are difficult to reverse as most of the patients belongs to higher age. Availability of restrained diets are rate limiting. Prospective symptomatic screening in large population with high rates of consanguinity & interbreeding will likely to decreased neonatal and infant mortality rate.
