A search for genetic loci involved in predisposition to bipolar mood disorder in the population of Antioquia, Colombia.

We are collecting a bipolar disorder type 1 study sample from the province of Antioquia in Colombia. Historical demography data and genetic founder effects indicate that this population constitutes an internal isolate. Through review of clinical records and family interviews, 22 nuclear families with multiple cases of bipolar 1 have been identified. Extension of pedigrees has detected 227 living individuals with psychiatric disorders. Patients are being assessed using the Diagnostic Interview for Genetic Studies (NIMH) and a best estimate procedure. Thus far 76 individuals have been confirmed as bipolar 1, 3 as bipolar 2, 22 as major depression and 23 have other psychiatric diagnoses. A further 98 sporadic bipolar 1 cases have been identified and confirmed by DIGS. An estimate of the power to detect linkage to a major ocus in the current pedigree set was obtained by simulation. The model used assumes a disease allele frequency of 0.003, penetrances set to 0.01, 0.81 and 0.9 (for genotypes NN, ND and ND) and a 4 allele marker at 5cM from the disease locus. These simulations indicate that, in the best-cocumented pedigrees, the current power to detect a lod score greater than 1 ranges between 33 and 86%.