<prompt> Prevalence of schizophrenia in dizygotic twins of schizophrenic patient is401120.10  <response>: Usual prevalence in general population is 0.5 to 1 and 40 in child with both parents being schizophrenic. Among dizygotic twins, it is 12 if a parent is schizophrenic Ref: Essentials of postgraduate psychiatry By JN Vyas 1st ed Pg 386 