Distribution of the CCR5delta32 allele (gene variant CCR5) in Rondônia, Western Amazonian region, Brazil

Since around 1723, on the occasion of its initial colonization by Europeans, Rondonia has received successive waves of immigrants. This has been further swelled by individuals from northeastern Brazil, who began entering at the beginning of the twentieth century. The ethnic composition varies across the state according to the various sites of settlement of each wave of immigrants. We analyzed the frequency of the CCR5L32 allele of the CCR5 chemokine receptor, which is considered a Caucasian marker, in five sample sets from the population. Four were collected in Porto Velho, the state capital and the site of several waves of migration. Of these, two, from the Hospital de Base were comprised of HB Mothers and HB Newborns presenting allele frequencies of 3.5 percent and 3.1 percent, respectively, a third from the peri-urban neighborhoods of Candelária/Bate-Estaca (1.8 percent), whereas a fourth, from the Research Center on Tropical Medicine/CEPEM (0.6 percent), was composed of malaria patients under treament. The fifth sample (3.4 percent) came from the inland Quilombola village of Pedras Negras. Two homozygous individuals (CCR5Δ32/CCR5Δ32) were detected among the HB Mother samples. The frequency of this allele was heterogeneous and higher where the European inflow was more pronounced. The presence of the allele in Pedras Negras revealed European miscegenation in a community largely comprising Quilombolas.

Genetic systems and biological traits in normal and chagasic individuals from a brazilian sample

Estudou-se a distribuiçäo de fenótipos de 11 sistemas genéticos (ACP1, ADA, ESA, PEPA, Hp, Hb, ESD, ABO, Rb, CAII and GLO) em relaçäo à doença de Chagas. Näo foi encontrada associaçäo significante entre esses polimorfismos e a infecçäo por T. cruzi, como também näo se verificou alteraçöes no eletrocardiograma (ECG). Foi detectado um possível efeito biológico do sexo sobre ECG. Por outro lado, um efeito racial na infecçäo, postulado em outro estudo, näo foi confirmado no presente material, indicando ser espuria , essa associaçäo

Human red cell enzymes distribution in a population sample from bambui (Minas Gerais)

Trezentos e noventa indivíduos de uma populaçäo tri-híbrida brasileira foram estudados em relaçäo a 4 sistemas genéticos (ACP1, ESA, PEPA and ADA). Somente os alelos comuns foram detectados nesta populaçäo, com exceçäo do sistema ESA que apresentou frequencia polimórfica numa variante rara. Esta variante pode ser classificada como sendo ESA*Dmaci (Neel et al., 1977) or ESA*C (Tashian, 1965). Säo apresentadas as freqüências gênicas e fenotípicas e estas säo encontradas em distribuiçäo semelhante a de outras populaçöes descritas