The fact that Hungary and Finland had among the highest reported suicide rates in Europe has led to speculations about the possible involvement of a common genetic factor in this phenomenon (Reference Marusic and FarmerMarušič & Farmer, 2001). Both Finns and Hungarians, as some linguists believe, belong to the Finno-Ugrian family of ethnic groups, with certain similarities in their ancient language. The high suicide rates in the various groups of Finno-Ugrians suggested to Kondrichin (Reference Kondrichin1995) that ‘during the early stages of Finno-Ugrian ethnogenesis certain behavioural traits predisposing to suicide became fixed in the gene pool’.
We (Reference Hrdina and FaludiHrdina & Faludi, 2001) have examined the available molecular genetic data on serotonergic candidate genes and their allelic association with suicide (Reference Nielsen, Goldman and VirkkunenNielsen et al, 1994; Reference Du, Faludi and PalkovitsDu et al, 2000) for any similarities or differences in allelic frequencies between the various populations, particularly between Finns and Hungarians. A direct comparison between the findings of association between serotonergic gene polymorphism and suicidal behaviour is difficult, since in the reports of positive associations different phenotypes (suicide attempt, completed suicide) were investigated. However, if certain serotonergic gene variants increase the disposition for, or vulnerability to, suicide in some populations that share higher rates of suicide and that may share some similarities in their ethno-historical origins, then the frequency of these predisposing gene variants should be comparable in those populations.
Table 1 summarises the allelic distributions of serotonergic gene polymorphisms in some selected populations. It is clearly apparent that the allelic distributions of the two polymorphisms (5-HT transporter S/L polymorphism and tryptophan hydroxylase gene 218 A/C polymorphism) are remarkably different in Hungarian and Finnish populations. In fact, the frequencies of the S and L alleles of the 5-HT transporter in the Hungarian subjects are closer to those found in the British population.
Table 1 Allelic distribution of serotonergic gene polymorphisms in selected populations
| Population | 5-HT transporter gene S/L polymorphism | TPH gene 218 A/C polymorphism | ||
|---|---|---|---|---|
| S allele (%) | L allele (%) | Allele A (%) | Allele C (%) | |
| Hungarian | 48.8 | 51.2 | 46.4 | 53.6 |
| Finnish | 33.0 | 67.0 | 35.0 | 65.0 |
| British | 45.6 | 54.4 | 39.1 | 60.9 |
The limited scientific evidence so far would suggest that there is no Finno-Ugrian ‘suicide gene’ or a shared genetic risk factor. It is unlikely that such a complex phenomenon as suicidal behaviour is genetically determined by a single gene or even a few gene variants. A more likely scenario is that the genetic contribution to suicide will be represented by small size effects of many gene variants associated with processes involved in suicidal behaviour, and by interaction of these genetic factors with environmental ones.
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