Northwestern Medicine scientists have discovered a biomarker for one type of autism within patients’ cerebrospinal fluid (CSF), according to a study published online on December 17, 2021 in Neuron. The article is titled “Shed CNTNAP2 Ectodomain Is Detectable in CSF and Regulates Ca2+ Homeostasis and Network Synchrony Via PMCA2/ATP2B2.” This biomarker’s presence helps establish a link between autism and epilepsy, conditions which often co-occur but whose conjunctive mechanisms remain unknown, according to Peter Penzes, PhD, the Ruth and Evelyn Dunbar Professor of Psychiatry and Behavioral Sciences, Professor of Neuroscience and Pharmacology, at Northwestern Medicine, and senior author of the study. “There’s too much excitation and too little inhibition in the brain, which can impact both autism and epilepsy,” said Dr. Penzes (photo), who is also Director of the Center for Autism and Neurodevelopment at Northwestern Medicine. “This is the first report of a biomarker for autism in cerebrospinal fluid.”