A Single Dominant Gene Still Cannot Account for the Transmission of Schizophrenia

Abstract

To the Editor.— Holzman et al¹ have written another in a series of thought-provoking reports describing the nature of the association between eye movement dysfunctions (EMDs) and schizophrenia. Although these researchers have convincingly established the existence of a familial association between EMDs and schizophrenia, we question whether their single dominant gene model can account for the joint transmission of these two characteristics. Holzman et al, in explicitly formulating a model for the joint transmission of schizophrenia and EMDs, necessarily propose a model for the familial transmission of schizophrenia. The validity of their model should be judged in relation to the large research literature aimed at characterizing the genetic transmission of schizophrenia.² The latent trait model proposed by Holzman et al assumes that the transmission of schizophrenia, and for that matter EMDs, is due entirely to the segregation of two alleles (eg, genes a and A) at a