Systematic approach to diagnose inborn neurometabolic disorders

Abstract

There is no dearth of literature detailing individual inborn neurometabolic disorders (INMDs), but it is hard to find a systematic approach to precisely diagnose these. Early diagnosis can go a long way in managing them and improving quality of life and cure in some cases. A systematic structured approach taking into account age, type of presentation, clinical features, imaging, biochemical tests, histopathology and molecular diagnostics often helps in arriving at a particular diagnosis, or a broad category of disorders, which helps in further management. Newer treatment options such as bone marrow transplantation, umbilical cord blood stem cell transplantation, enzyme substitution, somatic gene therapy, and fetal neuronal transplants have given a ray of hope, making it imperative to arrive at early diagnosis of these conditions. Even if a child is lost to inborn error of metabolism (IEM), the cord blood of a normal sibling may be frozen as a reservoir for stem cells for an affected sibling in future pregnancies. In this chapter, we would try to evolve a systematic approach for diagnosis of IEMs and to narrow down the list of differentials. This will lead to cost-effective yet precise biochemical, genetic, and molecular tests to arrive at a final diagnosis.