Tourette syndrome (TS) is a highly heritable neuropsychiatric disorder characterised by motor and vocal tics. Despite decades of research, the aetiology of TS has remained elusive. Recent successes in gene discovery backed by rapidly advancing genomic technologies have given us new insights into the genetic basis of the disorder, but the growing collection of rare and disparate findings have added confusion and complexity to the attempts to translate these findings into neurobiological mechanisms resulting in symptom genesis. In this review, we explore a previously unrecognised genetic link between TS and a competing series of trans-synaptic complexes (neurexins (NRXNs), neuroligins (NLGNs), leucine-rich repeat transmembrane proteins (LRRTMs), leucine rich repeat neuronals (LRRNs) and cerebellin precursor 2 (CBLN2)) that links it with autism spectrum disorder through neurodevelopmental pathways. The emergent neuropathogenetic model integrates all five genes so far found to be uniquely disrupted in TS into a single pathogenetic chain of events described in context with clinical and research implications.

With increasing use of herbal medicines for chronic or serious illness, relevant quality assurance methods are essential for making claims of therapeutic benefit. Adequate demonstration of safety and efficacy based on chemical composition and ensuring consistency between manufactured batches is critical. To date, there has been no uniform standard approach or detailed framework provided to industry for selecting relevant chemical markers used to standardize herbal products. We developed the Herbal Marker Ranking System (Herb MaRS) providing guidance on prioritizing the selection of chemical markers for quality control of complex multi-herb mixtures, while also taking into account the bioactivity in relation to the symptoms of the disease and its concentration in the formula. We apply the Herb MaRS evaluation criteria to a seven-herb formulation for the treatment of irritable bowel syndrome with constipation. Our ranking scale accommodates the clinical and pharmacological use of the formulation and its claimed indications.