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Serotonin transporter (5-HTT) gene polymorphisms and susceptibility to cocaine dependence among African-American individuals

Item Type:Article
Title:Serotonin transporter (5-HTT) gene polymorphisms and susceptibility to cocaine dependence among African-American individuals
Creators Name:Patkar, A.A. and Berrettini, W.H. and Hoehe, M.R. and Hill, K.P. and Sterling, R.C. and Gottheil, E. and Weinstein, S.P.
Abstract:Studies indicate that the serotonin system, particularly the serotonin transporter (5-HTT), may modulate the central effects of cocaine. We investigated whether a polymorphism in the 5′ promotor region (5-HTTLPR) of the 5-HTT gene confers susceptibility to cocaine dependence. One hundred and ninety-seven cocaine-dependent African-American subjects and 101 controls were studied. Polymerase chain reaction based genotyping of a biallelic repeat polymorphism in the 5′ promotor region yielded 2 alleles containing 484 (S) and 528 bp (L) repeats, respectively. There were no significant differences between controls of European background (n=40) and African-American controls (n=61) in distribution of genotypes (European: LL=32.5%, LS=40.0%, SS=27.5%; African-American: LL=27.9%, LS=57.4%, SS=14.7%) (X 2=3.60, df=2, p=0.16) or allele frequencies (European: L=52.5%, S=47.5%; African-American: L=56.6%, S=43.4%) (X 2=2.21, df=1, p=0.13). When cocaine patients were compared to an ethnically diverse control group (n=101), frequencies of the L variant (65.0%) were signicantly higher while the S variant (35.0%) was less frequent among cocaine patients compared to controls (L=53.9%, S=46.1%) (X 2=6.83, df=1, p<0.01). Similarly, there were more cocaine patients with the LL genotype (41.1%) and less with the SS genotype (11.2%) compared to controls (LL=29.7%, SS=21.8%) (X 2=7.43, df=2, p<0.05). However, after restricting controls to African-American individuals only (n=61), cocaine subjects and controls did not differ significantly with respect to genotype distribution (X 2=4.24, df=2, p=0.12) or allele frequencies (X 2=2.83, df=1, p=0.10). In conclusion, although comparisons with a heterogeneous control group indicated a possible association between allelic variants of 5-HTTLPR and cocaine dependence among African-American cocaine subjects, this relationship was not observed when the control group was limited to African-American people only. Our findings need to be confirmed on larger samples of ethnically matched individuals.
Source:Addiction Biology
Publisher:Carfax Publishing
Page Range:337-345
Date:1 January 2001
Official Publication:https://doi.org/10.1080/13556210020077064
PubMed:View item in PubMed

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