So Close, So Far Away: Analysis of Surnames in a Town of Twins (Cândido Godói, Brazil)

Abstract

SummaryCândido Godói is a small Brazilian town known for high rates of twin birth. In 2011, a genetic study showed that this localized high rate of twin births could be explained by a genetic founder effect. Here we used isonymic analysis and surname distribution to identify population subgroups within 5316 inhabitants and 665 different surnames. Four clusters were constructed based on different twin rates (P < 0.001; MRPP test). Fisher´s α and consanguinity index showed low and high values, respectively, corresponding with observed values in isolated communities with high levels of genetic drift. Values of A and B estimators confirmed population isolation. Three boundaries were identified with Monmonier´s maximum difference algorithm (P = 0.007). Inside the isolated sections, surnames of different geographic origins, language, and religion were represented. With an adequate statistical methodology, surname analyses provided a close approximation of historic and socioeconomic background at the moment of colony settlement. In this context, the maintenance of social and cultural practices had strong implications for the population´s structure leading to drift processes in this small town, supporting the previous genetic study.

Epidemiological aspects of hereditary fructose intolerance: A database study

“…Similar frequency patterns have been observed in European patients with Smith‐Lemli‐Opitz syndrome (Witsch‐Baumgartner et al, 2001). Thereafter, a founder effect and preferential crossings according to origin or religion (De Oliveira et al, 2013) may be acting to maintain the frequency of this allele among patients from North and South American populations (4%) (Table 1).…”

“…Due to the distribution on the European continent, it is possible to imagine that this variant appeared in Eastern Europe and has spread to et al, 2001). Thereafter, a founder effect and preferential crossings according to origin or religion (De Oliveira et al, 2013) may be acting to maintain the frequency of this allele among patients from North and South American populations (4%) (Table 1).…”

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“…Em outro trabalho, foram estudados os sobrenomes de todos os residentes em CG como um indicador de tipos de casamentos e também localizamos geograficamente todas as residências onde os gêmeos nasceram. Deste modo, encontramos altos índices de endogamia junto com baixa dispersão populacional especialmente na LSP, onde sabidamente registravam-se maiores taxas de gemelaridade 44 .…”

Population medical genetics: translating science to the community

“…We surveyed 6,262 baptism records from 1927 to 2008 and tested for temporal trends and found no evidence of a spurt of twinning between or from the years 1964-1968, when Mengele was supposedly there (Tagliani-Ribeiro et al , 2011). Moreover the use of surnames revealed that the mothers of twins had higher inbreeding coefficients than the mothers of singletons (De Oliveira et al , 2013). Our findings were presented and discussed with the population again on a Sunday, in the church community saloon, before going for publication.…”