Newborn screening for inborn errors of metabolism- Dried blood spot testing and Tandem mass spectrometric techniques

Inborn errors of metabolism (IEM) are a genetically disparate group of disorders arising out of defects in metabolic pathways leading to the excessive accumulation of metabolites. With development of the dried blood spot and tandem mass spectrometry (TMS), routinely assessing newborns for IEM’s, also referred to as newborn screening (NBS) has been made largely possible. Several IEM’s have a potential net benefit of screening, i.e. they are potentially treatable early in the course of disease before the onset of irreversible damage. NBS is a largely ignored facet in the pediatric health landscape of India and except for a minority of premier institutions, routine screenings incorporating testing for core disorders is not generally performed. It is only after accretions of obvious signs and symptoms are brought to the attention of a pediatrician that a high clinical suspicion in the direction of a metabolic disorder is finally elicited, which often results in delayed diagnosis. The single blood spot specimen detection kit is an inexpensive screening device which can detect with high and sensitivity and specificity several IEM’s such as amino acid disorders and organic acidemias. Further confirmations are then made by techniques such as TMS. We plan to review the various screening tests such as dried blood spot and confirmatory testing by TMS for timely detection of major preventable IEM’s.