UCLA scientists have discovered that infants who possess a specific immune gene that too closely resembles their mothers' are more likely to develop schizophrenia later in life. Reported in the October issue of the American Journal of Human Genetics, the study suggests that the genetic match may increase fetal susceptibility to schizophrenia, particularly in females.
HLA-B is one of a family of genes called the human leukocyte antigen (HLA) complex, which helps the immune system distinguish the body's own proteins from those made by foreign invaders, such as viruses and bacteria. The developing fetus inherits one copy of the HLA-B gene from each parent.
"Our findings clearly suggest that schizophrenia risk rises, especially in daughters, when the child's HLA-B gene too closely matches its mother's," explained Christina Palmer, Ph.D, UCLA associate professor of psychiatry and human genetics and a researcher at the Semel Institute for Neuroscience and Human Behavior. "We don't know whether sons who match are not affected -- or are more affected and less likely to come to term."
In 2002, Palmer and her colleagues discovered that infants are twice as likely to develop schizophrenia later in life when they possess a cell protein called Rhesus (Rh) factor that their mothers lack. Later studies found that male babies were more vulnerable to the consequences of Rh incompatibility than female infants.
The UCLA team hypothesized that females must possess a different fetal risk factor that predisposes them to schizophrenia. They decided to focus on HLA-B, which previous studies had linked to prenatal complications, like preeclampsia and low birth weight, that in turn have been associated with schizophrenia.
The researchers studied a group of 274 Finnish families in which at least one child had been diagnosed with schizophrenia or a related psychosis. In this group, 484 offspring had been diagnosed with the disease.'"/>