Schizophrenia Daily News Blog

Schizophrenia and Bipolar Genetics

Schizophrenia and Bipolar Disorder Genetic Links Substantiated

In recently-published research from the Journal of Medical Genetics, it has been noted that there is increasingly solid evidence that there are specific "susceptibility genes" that are shared between schizophrenia and bipolar disorder -- genes that make a person more likely to get either schizophrenia or bipolar disorder.

The researchers stated that "Much work has been done to identify susceptibility genes in schizophrenia and bipolar disorder. Several well established linkages have emerged in schizophrenia. Strongly supported regions are 6p24-22, 1q21-22, and 13q32-34, while other promising regions include 8p21-22, 6q16-25, 22q11-12, 5q21-q33, 10p15-p11, and 1q42."

    "Genomic regions of interest in bipolar disorder include 6q16-q22, 12q23-q24, and regions of 9p22-p21, 10q21-q22, 14q24-q32, 13q32-q34, 22q11-q22, and chromosome 18. Recently, specific genes or loci have been implicated in both disorders and, crucially, replicated. Current evidence supports NRG1, DTNBP1, DISC1, DAOA(G72), DAO, and RGS4 as schizophrenia susceptibility loci," wrote N. Craddock and colleagues, Cardiff University.

    "For bipolar disorder the strongest evidence supports DAOA(G72) and BDNF. Increasing evidence suggests an overlap in genetic susceptibility across the traditional classification systems that dichotomised psychotic disorders into schizophrenia or bipolar disorder, most notably with association findings at DAOA(G72), DISC1, and NRG1," they added.

    The researchers concluded, "Future identification of psychosis susceptibility genes will have a major impact on our understanding of disease pathophysiology and will lead to changes in classification and the clinical practice of psychiatry."

Source: Journal of Medical Genetics (The genetics of schizophrenia and bipolar disorder: Dissecting psychosis. J Med Genet, 2005;42(3):193-204).

Background Reading

Links between Bipolar Disorder and Schizophrenia Genetics

(1997): Genetics of Schizophrenia and Affective Disorders Overlap