Gamma‐aminobutyric acid levels in cerebrospinal fluid in neuropaediatric disorders

Aim Gamma‐aminobutyric acid (GABA) is a major modulator in brain maturation and its role in many different neurodevelopmental disorders has been widely reported. Although the involvement of GABA in different disorders has been related to its regulatory function as an inhibitory neurotransmitter in the mature brain, co‐transmitter, and signalling molecule, little is known about its role as a clinical biomarker in neuropaediatric disorders. The aim of this study is to report the cerebrospinal fluid (CSF) free‐GABA concentrations in a large cohort of patients (n=85) with different neurological disorders. Method GABA was measured in the CSF of neuropaediatric patients using capillary electrophoresis with laser‐induced fluorescence detection. Other neurotransmitters (amino acids and monoamines) were also analysed. Results GABA concentrations in CSF were abnormal, with a greater frequency (44%) than monoamines (20%) in neuropaediatric patients compared with our reference values. Although we included a few patients with inborn errors of metabolism, GABA levels in CSF were more frequently abnormal in metabolic disorders than in other nosological groups. Interpretation Our work suggests further research into brain GABAergic status in neuropaediatric disorders, which could also lead to new therapeutic strategies. What this paper adds Homeostasis of GABA seems more vulnerable than that of monoamines in the developing brain. The highest GABA levels are found in the primary GABA neurotransmitter disorder SSADH deficiency. GABA alterations are not specific for any clinical or neuroimaging presentation. Resumen Niveles de acido gama‐aminobutírico en líquido cefalorraquídeo en trastornos neuropediátricos Objetivo El ácido gama‐aminobutírico (GABA) es un modulador mayor en la maduración cerebral y su función en diversos trastornos del neurodesarrollo ha sido ampliamente descripta. La función del GABA en diferentes trastornos se ha relacionado con su función reguladora como neurotransmisor inhibidor en la madurez cerebral, así como co‐transmisor y como molécula indicadora, sin embargo, poco se conoce como bio‐marcador clínico en trastornos neuropediátricos. El objetivo de este estudio es reportar las concentraciones de GABA‐libre en líquido cefalorraquídeo (LCR) en una gran cohorte de pacientes (n=85) con diferentes trastornos neurológicos. Método El GABA fue medido en LCR de pacientes neuropediátricos utilizando electroforesis capilar con detección de fluorescencia inducid