Protein Oct-6 is not a biological marker for schizophrenia

Oct 23 2005

The protein Oct-6 is not a biological marker for schizophrenia. The results of a study published today in the open access journal BMC Psychiatry contradict previous findings and show that Oct-6, a protein involved in neurodevelopment, is normally expressed in the adult brain and cannot be used to identify patients with schizophrenia.

Oct-6 was shown to be expressed in the brain of patients diagnosed with schizophrenia, but not in the brain of healthy individuals, in a study led by Jack Price and published in the July 2002 issue of The American Journal of Psychiatry. Kirenjeet Ubhi and Jack Price, from Kings College London, UK have now replicated Price's original study and extended it. Their findings contradict Price's earlier study.

Events affecting brain development are thought to underlie the occurrence of schizophrenia in later life. Oct-6 plays a crucial role in neurodevelopment, and a genetic variation within the Oct-6 gene has been linked to a subset of patients with schizophrenia and bipolar disorder; therefore, Oct-6 seemed like a good candidate for a biological marker for these disorders.

Ubhi and Price extended Price's original study to include patients with bipolar disorder and major depression – it has been suggested that schizophrenia shares a common pathology with these disorders. They analysed post-mortem brain samples from 3 groups of 15 patients. The first group had been diagnosed with schizophrenia, the second group with bipolar disorder and the third group with major depressive disorder. They used 15 brain samples of matched healthy individuals as controls. Oct-6 mRNA and protein expression were determined by in-situ hybridization and immunostaining respectively.

Contrary to their previous results, Ubhi and Price found no difference in Oct-6 protein or mRNA expression between patients and controls.

http://www.biomedcentral.com/bmcpsychiatry/