Lack of association between a serotonin transporter promoter polymorphism and BP1 in Antioquia, Colombia

We have examined the frequency of a functional length polymorphism in the promoter region of the serotonin transporter (5-HTTLPR) in a case/control sample for bipolar mood disorder type 1. Patients (N=98) and controls (N= 104) were collected from the isolated population of Antioquia, Colombia. Cases were evaluated using the Diagnostic Interview for Genetic Studies (NIMH). Normal controls were randomly selected individuals matched with cases for sex and over 35 years old. Genomic DNA samples were genotyped using the experimental conditions reported by Lesch et al. (Science 274, 1527-1531). Allele frequencies for the cases were 1 = 0.52 s = 0.48 and for the controls 1 = 0.47 s = 0.53 . Genotype frequencies for the cases were 1/1= 0.29 1/s= 0.45 s/ s= 0.26 and for the controls: 1/1= 0.19 1/s= 0.56 s/s= 0.25. No statistically significant deviation from Hardy Weinberg expectation was detected in the two groups. No statistically significant difference in the allele (chi square 0.47, p=0.493) or genotype (chi square 3.08, p=0.214) frequencies was observed between cases and controls. Thus we detected no evidence of association of this polymorphism with bipolar disorder in this sample

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%

An association study of bipolar mood disorder type I with the 5-HTTLPR serotonin transporter polymorphism in a population isolate from Colombia

The short variant of a functional length polymorphism in the promoter region of the serotonin transporter has been associated with several behavioural and psychiatric traits, including bipolar mood disorder. The same short allele has also been implicated as a modifier of the bipolar phenotype. Here we evaluate the etiologic/modifier role of this polymorphism in a case (N=103) / control (N=112) sample for bipolar mood disorder (type I) collected from an isolated South American population. We did not detect an association between bipolar disorder and the 5-HTT promoter polymorphism in this sample. However, an excess of the short allele was seen in younger cases and in cases with psychotic symptoms. When combined with data from the literature, the increased frequency of the short allele in patients with psychotic symptoms was statistically significant