A proof-of-concept study: evaluating the applicability of high-throughput screening data and read-across tools for food relevant chemicals

Abstract

Tourette syndrome (TS) is a chronic neuropsychiatric disorder with an unknown etiology characterized by motor and vocal tics. The onset of tics occurs most commonly in early childhood around the age of 5–7 years, and the disorder follows a typical waxing and waning pattern over the years (Freeman et al., 2000; Leckman, 2002). The severity and frequency of tics increase during the prepubescent years and decline most commonly by early adulthood (Leckman, 2002; Bloch and Leckman, 2009). The majority of TS patients will experience either a stabilization or remission of tics by adulthood (Cavanna and Rickards, 2013). TS is considered an inherited disorder, although the exact genetic abnormality remains unknown. The fact that the beginning of symptoms is present during the course of maturation suggests that it is a developmental disorder (Felling and Singer, 2011). TS is considered a relatively common disorder affecting an estimated 1% of the population and occurring four or five times more commonly in males than in females (Robertson et al., 2009). Diagnosis is performed during childhood after the documentation of persistent involuntary motor and phonic tics over a period of at least 1 year without a symptom-free period of three consecutive months (American Psychiatric Association, 2013). Deep brain stimulation can be considered in TS patients refractory to behavioral therapy or drug treatment. Since 1999, less than 200 TS patients have been treated with DBS. Most common targets are the medial part of the thalamus, the globus pallidus internus, and the nucleus accumbens.