RT Journal
A1 Holzman PS, Matthysse S, Levy DL
T1 Eye tracking dysfunction is associated with partial trisomy of chromosome 5 and schizophrenia: A response
JF Archives of General Psychiatry
JO Archives of General Psychiatry
YR 1989
FD August 1
VO 46
IS 8
SP 756
OP 757
DO 10.1001/archpsyc.1989.01810080086013
UL http://dx.doi.org/10.1001/archpsyc.1989.01810080086013
AB To the Editor.— 
    In their letter that appeared in the December 1988 issue of the Archives, Iacono et al1 presented interesting data showing the co-occurrence of schizophrenia and eye movement dysfunctions (EMDs) in a proband and his schizophrenic maternal uncle, both of whom also had a partial trisomy of chromosome 5. Iacono et al interpret these data as supporting the latent trait hypothesis, and we agree. We have, however, some reservations and concerns.Iacono et al give the impression that one-to-one co-occurrence of EMDs and schizophrenia is predicted by the latent trait model. If readers will examine Fig 2 of our article that appeared in the July 1988 issue of the Archives,2 which we reprint here (Figure) and in which we present a validation of the model using offspring of discordant twins, they will see that in this representative family EMDs and schizophrenia did not occur jointly in