Analysis of the CCR5 gene coding region diversity in five South American populations reveals two new non-synonymous alleles in Amerindians and high CCR5*D32 frequency in Euro-Brazilians

The CC chemokine receptor 5 (CCR5) molecule is an important co-receptor for HIV. The effect of the CCR5*D32 allele in susceptibility to HIV infection and AIDS disease is well known. Other alleles than CCR5*D32 have not been analysed before, neither in Amerindians nor in the majority of the populations all over the world. We investigated the distribution of the CCR5 coding region alleles in South Brazil and noticed a high CCR5*D32 frequency in the Euro-Brazilian population of the Paraná State (9.3%), which is the highest thus far reported for Latin America. The D32 frequency is even higher among the Euro-Brazilian Mennonites (14.2%). This allele is uncommon in Afro-Brazilians (2.0%), rare in the Guarani Amerindians (0.4%) and absent in the Kaingang Amerindians and the Oriental-Brazilians. R223Q is common in the Oriental-Brazilians (7.7%) and R60S in the Afro-Brazilians (5.0%). A29S and L55Q present an impaired response to β-chemokines and occurred in Afro- and Euro-Brazilians with cumulative frequencies of 4.4% and 2.7%, respectively. Two new non-synonymous alleles were found in Amerindians: C323F (g.3729G > T) in Guarani (1.4%) and Y68C (g.2964A > G) in Kaingang (10.3%). The functional characteristics of these alleles should be defined and considered in epidemiological investigations about HIV-1 infection and AIDS incidence in Amerindian populations

Frequencies of the Butyrylcholinesterase K Mutation in Brazilian Populations of European and African Origin

The frequency of the butyrylcholinesterase K mutation was calculated on the basis of data obtained by polymerase chain reaction primer-introduced restriction analysis (PCR-PIRA). The population sample was composed of 177 Brazilians: 95 whites of predominantly European ancestry and 82 admixed individuals (European and African origin). The frequencies—18.4 ± 2.8% for whites and 17.1 ± 2.9% for admixed did not differ from those previously obtained in North America, Scotland, Japan, and Denmark. The occurrence of the K mutation in Europeans, East Asians, and Africans suggests a relatively old origin for this mutation, and the similar frequencies found in these populations may suggest the operation of selective forces