New contribution to the genetics of the Basques: heterogeneity in the esterase D subtype distribution

A random sample of 1,491 individuals from three Basque provinces was studied for the red-cell esterase D (ESD) polymorphism by means of isoelectric focusing. The following allele frequencies were observed: Vizcaya, ESD*1 = 0.933, ESD*2 = 0.058, ESD*5 = 0.009; Guipuzcoa, ESD*1 = 0.938, ESD*2 = 0.053, ESD*5 = 0.009; and Alava, ESD*1 = 0.894, ESD*2 = 0.088, ESD*5 = 0.018. The Basques from Vizcaya and Guipuzcoa display the lowest values for allele ESD*5 of any European population studied to date. The value obtained for this allele in the Basque population of Alava is significantly higher than those found in the other two Basque samples. This, together with the fact that Basques from Alava display the lowest ESD*1 frequency of any Basque series, suggests that there are genetic differences between Basque provinces.