RT Journal
A1 Iacono WG, Bassett AS, Jones BD
T1 Eye tracking dysfunction is associated with partial trisomy of chromosome 5 and schizophrenia: A response-reply
JF Archives of General Psychiatry
JO Archives of General Psychiatry
YR 1989
FD August 1
VO 46
IS 8
SP 757
OP 758
DO 10.1001/archpsyc.1989.01810080087014
UL http://dx.doi.org/10.1001/archpsyc.1989.01810080087014
AB In Reply.— 
    Our case study revealed that a proband and his maternal uncle, both of whom had partial trisomy of chromosome 5 and schizophrenia, also had abnormal smooth-pursuit eye tracking. The proband's mother, father, and brother, who had neither any psychiatric disorder nor the partial trisomy, displayed very good eye tracking performance. Although we are pleased that Holzman et al found these data supportive of their latent trait hypothesis, we do not share their reservations and concerns.If we assume that schizophrenia in the proband and uncle arose because they had the chromosomal anomaly, then finding abnormal pursuit tracking in the nonschizophrenic family members would not support the latent trait hypothesis. This family is interesting presumably because the trisomic individuals possess a special "genotype" (partial trisomy chromosome 5) associated with schizophrenia, while the other members of the family do not. There is, therefore, no reason to expect the nontrisomic, psychiatrically healthy