Delta-aminolevulinate dehydrase (ALAD) polymorphism in mixed Brazilians from the State of Bahia.

Electrophoretic polymorphism of delta-aminolevulinate dehydrase (ALAD) was studied on 519 individuals from Bahia, Brazil. Subjective assessment of Black ancestries carried out in a five point visual scale (White, Light Mulatto, Medium Mulatto, Dark Mulatto and Black) allowed to show that the ALAD*2 allele frequency decreases from 8% in Whites to 0% in Blacks. These findings agree with previous reports of ALAD in Africans, American Indians and Spanish. The powerful peculiarity of the ALAD system in assessing racial admixture is stressed.