Sniffing Out Genetic Risk Markers

Olfactory defects may indicate a genetic predisposition to schizophrenia, even in the absence of any other symptoms, according to a study concluded last month at the University of Pennsylvania.

Bruce Turetsky and his team made the astonishing discovery that the olfactory bulbs of first-degree relatives of schizophrenia patients are smaller in volume than those of individuals with no family history of the disease. When the scientists compared the brain activity of 14 unaffected direct relatives of schizophrenia patients against a 20-subject control group, they discovered significant impairment of scent detection and identification in the first group.

“While these findings must be considered preliminary,” concluded the researchers, “they are consistent with the conclusion that neurophysiological disturbances in the olfactory system may be sensitive endophenotypic markers (characteristics that reflect the actions of genes predisposing an individual to a disorder) of genetic vulnerability to schizophrenia.”