Neurometabolic Testing in Developmental Delay

Abstract

The goal of this study was to examine the usefulness of neurometabolic testing in patients with unexplained developmental delay. We included 118 patients from ages 3 months to 13 years. The evaluation was conducted according to a protocol that called for stepwise investigations with the intention to minimize unnecessary tests. Clinical and neuroradiologic abnormalities were used as guidelines for the type and extent of the neurometabolic work-up. Based on our results, a diagnosis for a neurometabolic disorder was established in 16 patients (13.6%). Findings regarding abnormal metabolites (amino acids, ammonia, lactate, pyruvate, urine organic acids) did not lead to a diagnosis but to further investigations. Abnormalities in lysosomal enzymes, very-long-chain fatty acids, and urine mucopolysaccharides were definitive in establishing a diagnosis. In conclusion, in children with slowly progressing development with no apparent cause, there is a need for guidelines regarding the type of patients who need to be tested and the kind and extent of neurometabolic diagnostic work-up.