The region coding
human leukocyte antigen (HLA) on chromosome 6q21 was shown to be associated with both the vulnerability to
schizophrenia and presence of eye movement disturbances (EMD). The aim of this preliminary study was to investigate how individual class I and II
HLA antigens in schizophrenic patients may be related to
schizophrenia and to the intensity of two kinds of EMD: fixation and smooth pursuit. The incidence of
HLA antigens was compared between 40 schizophrenic patients (17 male, 23 female) and 198 healthy control subjects (112 male, 86 female). In schizophrenic patients, the intensity of EMD assessed by infrared reflectometry and quantified on a scale from 0 to 3 was correlated with the incidence of
HLA antigens. A number of differences regarding
HLA antigens were found between schizophrenic patients and healthy subjects. Significant correlation was also obtained between some EMD and a number of
HLA antigens.
Antigens A24 and A28 were found to occur in different frequencies in schizophrenic patients and healthy control subjects. They also correlated with EMD on the fixation and smooth pursuit tests. The results obtained show an association between
HLA antigens and EMD as an endophenotypic marker of
schizophrenia, and may add to other findings on susceptibility loci for
schizophrenia on chromosome 6p21. A limitation of this study is a small number of investigated patients with
schizophrenia.