“…The known coexistence of DJS and RS in one family (Arias, 1961) makes it likely that these disorders are variable manifestations of the same mutant gene, and the most generally held view has been that inheritance is in autosomal dominant fashion (Beker and Read, 1958;Mandema et al, 1960;Butt et al, 1966). However, while Butt et al (1966) favoured autosomal dominance they also suggested that the proband in their large family and perhaps one or more of her siblings may have been homozygous for the gene whereas all the other subclinically affected persons were heterozygotes.…”