Neonatal screening for inborn errors of metabolism using tandem mass spectrometry: experience of the pilot study in Andhra Pradesh, India.

OBJECTIVE To estimate the prevalence of the Inborn Errors of Metabolism (IEM), evaluate biomarker distributions and determine benefits of screening for the inborn errors of metabolism in Andhra Pradesh, India, using Tandem Mass Spectrometry (MS/MS). METHODS The 4,946 newborns born during the period 2006-2008 in four major Government Maternity Hospitals in a rural district in Andhra Pradesh, India, were screened at an established newborn screening laboratory in the US using their previously established norms. RESULTS Forty-seven neonates had out-of-range results (5 high probability; 28 low probability; 14 indeterminate). Two infants with disorders (carnitine uptake disorder and isovaleric aciduria) identified by screening are currently doing well. One infant with presumed glutaric aciduria type II, was deceased at the time of reporting. Another infant, with glutaric aciduria type I, became symptomatic and died at the age of 1 year despite early detection and treatment. A comparison of the concentrations of biomarkers among babies born in India and those born in Massachusetts, US, was also undertaken and significant differences were noted. CONCLUSIONS A high prevalence of disorders was observed, but to estimate the true extent of the IEM in India larger studies are required. This study also illustrates challenges encountered in disease management highlighting the importance of considering the access to confirmatory testing and continuing clinical care before implementing any large-scale NBS for conditions with resource-intensive health needs such as the IEM detected by MS/MS.