|Hunting for bipolar genes in patients who respond to lithium|
Edward R. Winstead
August 20, 2001
In a first step toward identifying susceptibility genes for bipolar disorder, researchers have scanned the genomes of patients who responded well to lithium therapy and their relatives. Chromosomes 15 and 7 might contain genes associated with the disease or responsiveness to lithium, according to analyses of the scan data.
Martin Alda, of the Department of Psychiatry at Dalhousie University in Halifax, Canada, led the study, which included 31 families. At least one affected individual per family remained relatively healthy while taking lithium for more than a decade.
A diagnosis of bipolar disorder can cover a range of mood-related conditions, but patients who respond to lithium tend to have similar types of disease and may constitute a biologically distinct subgroup. It is generally thought to be easier to detect genetic effects among individuals with similar rather than diverse genetic backgrounds.
"Selecting research subjects based on common patterns of response or non-response to a given pharmacological treatment may be useful to define genetically more homogeneous subgroups," the researchers write in Molecular Psychiatry.
The region of chromosome 15 falls near genes previously linked to bipolar disorder. The researchers hypothesize that the locus on chromosome 7 is related to drug responsiveness.
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