Persons with schizophrenia experience imaginary voices, visions and disorganized thoughts, and are handicapped when it comes to social life, which is detrimental to the affected individuals and the community. Although the pathogenesis of this mental disease has not been clearly elucidated, much evidence suggests that inheritance is of major etiological importance and multiple genetic components are implicated. Previous linkage studies of familial schizophrenia have led to the successful identification of numerous susceptibility loci covering many of the human chromosomes, including chromosome 1q, 5q, 6p22, 6p24, 8q21, 13q32, 15q13-14 and 22q11, etc. Necessities for further identification of candidate genes involved in familial schizophrenia by taking a genome-wide approach are listed as follows: