A novel point mutation in a class IV glucose-6-phosphate dehydrogenase variant (G6PD São Paulo) and polymorphic G6PD variants in São Paulo State, Brazil

In this study, we used red cell glucose-6-phosphate dehydrogenase (G6PD) activity to screen for G6PD-deficient individuals in 373 unrelated asymptomatic adult men who were working with insecticides (organophosphorus and carbamate) in dengue prevention programs in 27 cities in São Paulo State, Brazil. Twenty-one unrelated male children suspected of having erythroenzymopathy who were attended at hospitals in São Paulo city were also studied. Fifteen of the 373 adults and 12 of the 21 children were G6PD deficient. G6PD gene mutations were investigated in these G6PD-deficient individuals by using PCR-RFLP, PCR-SSCP analysis and DNA sequencing. Twelve G6PD A-202A/376G and two G6PD Seattle844C, as well as a new variant identified as G6PD São Paulo, were detected among adults, and 11 G6PD A-202A/376G and one G6PD Seattle844C were found among children. The novel mutation c.660C > G caused the replacement of isoleucine by methionine (I220M) in a region near the dimer interface of the molecule. The conservative nature of this mutation (substitution of a nonpolar aliphatic amino acid for another one) could explain why there was no corresponding change in the loss of G6PD activity (64.5 percent of normal activity in both cases).

Hemoglobinas anormais e deficiência de glicose -6- fosfato desidrogenase em Natal, RN / Abnormal hemoglobins and erythrocyte glucose -6- phosphate dehydrogenase deficiency in Natal, RN

Os autores reslizaram um estudo com a finalidade de determinar a prevalência de variantes hemoglobínicas e da deficiência de glicose-6-fosfato desidrogenase (G-6-PD) em uma amostra da populaçåo de Natal, RN. Foram analisadas 848 amostras de sangue de indivíduos do sexo masculino com idade compreendidas entre 18 e 20 anos. A investigaçåo das hemoglobinas anormais foi efetuada mediante eletroforese em acetato de celulose usando tampåo Tris-Glicina pH 8.6. A determinaçåo da atividade enzimática da G-6-PD foi feita utilizando o teste de reduçåo da metahemoglobina e confirmada pelo método semi-quantitativo. Os procedimentos utilizados mostraram que 14 (1,65 por cento) indivíduos estudados tinham hemoglobinas anormais, sendo 1,53 por cento e 0,12 por cento para os genótipos AS e AC, respectivamente. Dentre os indivíduos estudados, foram identificados 28 deficientes de G-6-PD, representando uma prevalência média de 3,30 por cento