Dr. Turecki and Colleagues Reply

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Back to table of contents Previous article Next article Letter to the EditorFull AccessDr. Turecki and Colleagues ReplyGUSTAVO TURECKI, M.D., PH.D., RICHARD BRIÈRE, PH.D., KAREN DEWAR, PH.D., ALAIN D. LESAGE, M.D., MONIQUE SÉGUIN, PH.D., NADIA CHAWKY, M.SC., CLAUDE VANIER, M.D., MARTIN ALDA, M.D., RIDHA JOOBER, M.D., CHAWKI BENKELFAT, M.D., and GUY A. ROULEAU, M.D., PH.D., GUSTAVO TURECKISearch for more papers by this author, M.D., PH.D., RICHARD BRIÈRESearch for more papers by this author, PH.D., KAREN DEWARSearch for more papers by this author, PH.D., ALAIN D. LESAGESearch for more papers by this author, M.D., MONIQUE SÉGUINSearch for more papers by this author, PH.D., NADIA CHAWKYSearch for more papers by this author, M.SC., CLAUDE VANIERSearch for more papers by this author, M.D., MARTIN ALDASearch for more papers by this author, M.D., RIDHA JOOBERSearch for more papers by this author, M.D., CHAWKI BENKELFATSearch for more papers by this author, M.D., and GUY A. ROULEAUSearch for more papers by this author, M.D., PH.D., Verdun, Que., CanadaPublished Online:1 Jan 2001https://doi.org/10.1176/appi.ajp.158.1.148AboutSectionsView EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail To the Editor: Drs. Hrdina and Du report the results they observed in a study (unpublished) in which they attempted to replicate our findings. In observing 17 depressed suicide subjects and 35 comparison subjects, they failed to find a relationship between variation at the T102C 5-HTR2A polymorphism and 5-HTR2A binding. As previously discussed (1), a possible explanation for this inconsistency may be related to the characteristics of the subjects included in our study, who were of French Canadian descent. This is a relatively young and isolated population that has a large background linkage disequilibrium (2). Thus, it is possible that a functional genetic variant located in a different coding or regulatory region of the 5-HTR2A gene, rather than the T102C silent polymorphism, may in fact be responsible for our positive results.This may not have been the case in the study by Drs. Hrdina and Du because they investigated subjects of Hungarian origin. Although they did not provide details about the specific ethnic composition of their study group, the Hungarian general population is composed of several different ethnic groups with admixture among most of them. The population is not known to have undergone any event leading to the presence of the relatively large linkage disequilibrium that may be observed in subjects chosen at random (3, 4).An additional point relates to ascertainment differences between the studies. Drs. Hrdina and Du have focused their attention on depressed suicide victims (Du et al., 1999). Our findings are not related to the phenotype, but rather to a relationship between genetic variation and 5-HTR2A binding. However, if there is less variation among binding levels in depressed patients, this group may have lower power to detect a positive association.