Biochemical Analyses of Cerebrospinal Fluid for the Diagnosis of Neurometabolic Conditions. What Can We Expect?

In this article, we review the state-of-the-art analysis of different biomarkers in the cerebrospinal fluid for the diagnosis of genetically conditioned, rare, neurometabolic diseases, including glucose transport defects, neurotransmitter (dopamine, serotonin, and gamma-aminobutyric acid) and pterin deficiencies, and vitamin defects (folate, vitamin B6, and thiamine) that affect the brain. The analysis of several key metabolites are detailed, which thus highlights the preanalytical and analytical factors that should be cautiously controlled to avoid misdiagnosis; moreover, these factors may facilitate an adequate interpretation of the biochemical profiles in the context of severe neuropediatric disorders. Secondary disturbances in these biomarkers, which are associated with other genetic or environmental conditions, are also detailed. Importantly, the early biochemical identification of biochemical disturbances in the cerebrospinal fluid may improve the clinical outcomes of a remarkable number of patients, who may exhibit good neurologic outcomes using the available therapies for these disorders.