“…Cases of discordance between dizygotic and monozygotic twins have been reported too [Stevenson and Scott, 1976;Carakushansky and Berthier, 19761. In spite of the sporadic occurrence in most cases, several reports of affected sibs have been published, consistent with both autosomal dominant [Barr et al, 1971;Beck, 1974;Bankier et al, 1985;Leavitt et al, 1985;Kumar et al, 1985;Robinson et al, 19851 and autosomal recessive transmission [Corda, 1966;Pearce et al, 1967;Mot1 and Opitz, 1971;Beratis et al, 1971;Lieber et al, 1973;Parisi et al, 1975;Beck and Mikkelsen, 19811. Many causal hypotheses have been discussed. Ptacek et al [19631 were the first to suggest that BDLS could be due to a n autosomal dominant mutation.…”