Molecular characterization of glucose-6-phosphate dehidrogenase deficiency in patients from the southern brazilian city of Porto Alegre, RS

Abstract

Glucose-6-phosphate dehydrogenase (G6PDH; EC 1.1.1.49) deficiency is one of the most common human enzymopathies throughout the world. Although most affected individuals are asymptomatic, there is a risk of neonatal jaundice and acute hemolytic anemia which can be triggered by infection, some pharmaceuticals and, in older individuals, eating fava beans. We characterized the molecular basis of G6PDH deficiency in a sample of 348 adults from Porto Alegre (population about 1.5 million), the capital of the southernmost Brazilian state of Rio Grande do Sul. Genomic DNA was extracted from peripheral blood leukocytes. We studied the three G6PDH mutations that appear to be the most frequent in Southern Brazil, the G202A and A376G A minus (A-) variants and the C563T Mediterranean (Med) variant. From July 2004 to October 2005, 348 patients (162 Females plus 186 males, age range 0 to 82 years) from Porto Alegre were referred to our laboratory for G6PDH analysis, 36 (9.7%) of which showed deficient G6PDH activity. These 36 patients and 34 randomly-selected non-deficient control individuals were submitted to molecular analysis which revealed a predominance of G6PDH A- allele among the deficient patients. The prevalence of the G6PDH A- variant agrees with its distribution among the ethnic groups that colonized RS, especially those of African, Portuguese, Spanish, and Italian origin.