Hurler-Scheie phenotype: a report of two pairs of inbred sibs.

Four cases from two families with dermatan sulfate mucopolysacchariduria who lack alpha-L-iduronidase in peripheral leukocytes are described. The clinical and roentgenographic features of these cases represent an intermediate phenotype between Hurler's syndrome and Scheie's syndrome, and both parents in each family are first cousins. In the presence of parental consanguinity, a phenotypic variation or a third mutant allele at the iduronidase locus seems to be a more reasonable explanation for these cases than a genetic compound.