NTRK1 and schizophrenia: For instance, the frequency of rs6336-T (H568Y) variant, which creates an additional potential site of TrkA autophosphorylation, correlates with the predisposition to schizophrenia in American and European populations (van Schijndel et al., 2009, 2011), although rs6336-T (H568Y) variant was identified as a protective factor in a number of experimental cohorts (van Schijndel et al., 2011).