Molecular analysis of G6PD variants in northern Italy: a study on the population from the Ferrara district

In the Ferrara district, an area south of the Po delta, four different variants of glucose-6-phosphate dehydrogenase (G6PD;E.C.1.1.49) have been described as a result of biochemical characterization of the enzyme protein: one was G6PD Mediterranean (G6PD Med) and three were local variants named Ferrara I, II, and III. The Ferrara I variant was recently analysed at the DNA level and shown to correspond to G6PD A^376G/202A, while the mutations causing the variants II and III, still remain unknown. We analysed the G6PD coding region of 18 apparently unrelated G6PD deficient subjects, whose families have lived in the Ferrara district for at least three generations: 12 subjects had G6PD Med^563T/1311T, 3, G6PD Santamaria^376G/542T and 2, G6PD A-^376G/202A. In one subject we found a new mutation, a GA transition at nucleotide 242 causing an ArgHis amino acid replacement at position 81. We named this new variant G6PD Lagosanto^{242 A}. Phenotypically the enzyme has nearly normal kinetic properties and appears different from the variants Ferrara II and III.