Screening for aminoacidurias and organic acidurias in patients with metabolic or neurological manifestations

Abstract

Inborn errors of metabolism (IEM) are a group of inherited disorders occurring due to a sin- gle gene defect, resulting in accumulation of an abnormal metabolite leading to varied mani- festations and complications. Early recognition and treatment are the best determinants of outcome in such patients. Objective: With the objective of providing a guide towards early di- agnosis of IEM among patients having strong clinical suspicion, we have screened 128 urine samples from patients with either metabolic or neurological features. Method: Urine samples were analysed for abnormal constituents like reducing sugar, proteins, ketone bodies by rou- tine laboratory chemical tests. Special tests were done for phenylketones, organic acids, keto- acids, tyrosine, mucopolysachharides supported by thin layer chromatography for amino- acidurias. Results: Most common positive tests reported in our study are, non specific general- ized aminoacidurias (58%), branched chain aminoacidurias (14%), tyrosinuria (13%), methlymalonic aciduria (7%) followed by mucopolysaccharidosis (4%) and phenylketonuria (2%). The common clinical manifestations observed among all participants were neurological features like convulsions (25.7%), delayed milestones (17.9%), and followed by metabolic aci- dosis (17.2%) and hypoglycemia (10.1%). Conclusion: High index of suspicion from clinicians supported by preliminary screening tests can aid in early presumptive diagnosis, which helps in initiating early treatment to prevent lethal neurological complications.