Occurrence of a rare variant of superoxide dismutase in Brazil.

During a paternity test performed in Porto Alegre, Brazil, a rare variant of superoxide dismutase, probably SOD A2, was found in a Caucasian child and the putative father. Studies of 1,700 unrelated white individuals from the same and nearby cities had never disclosed such a variant, which was also absent in 2,480 persons of other ethnic groups living in different regions of Brazil. The presence of this rare phenotype in the child and putative father led to the assignment of a very high probability of paternity to the latter.