Glyoxalase 1: a possible 'null' allele.

A three-generation family, ascertained through the presence of two diabetic sibs, provides segregation data suggestive of the existence of a null allele at the glyoxalase (GLO) locus. This conclusion is supported by the GLO 1 phenotype in two children from a GLO 2 father. These two children inherited the same paternal HLA allele, while two other sibs received GLO 2 with the other paternal HLA haplotype. The rest of the pedigree is in agreement with this suggestion, while the segregation of all other informative markers does not suggest nonpaternity.