The exact nature of the mechanism underlying the empirically
observed association of the HLA-A*03 gene with the delusional
disorder and paranoid schizophrenia remains
unknown; however, several genetic and environmental factors
may be involved in such an association. HLA generally
plays a critical role in the control of infectious and other
immune functions. Also, it is widely accepted that a disturbance
in neurodevelopment may be related to the development
of schizophrenia. Research has also shown that an
interaction betweenHLAand a perinatal or prenatal infection,
which can affect neurodevelopment, may be associated with
schizophrenia (35).