| Popis: |
Description of 3 cases of identical twins affected by concordant oxycephaly. In the first case, one of the twins had a son who was likewise afflicted by a typical scaphocephaly. In the second case, both children showed also a convergent concomitant strabismus, which was latent in one and manifest in the other, and moreover a concordant ptosis. In the third case, the oxycephaly was associated with cutis frontis gyrata homologous in both twins.A confrontation of the cases of oxycephaly in identical twins based on the literature and our personal cases, shows clearly a majority in favour of concordance : 25 concordant pairs as compared to 10 discordant ones; the fraternal twins (7-8 cases) are all discordant as regards oxycephaly. The cases of discordant oxycephaly in monozygotic twins must therefore be interpreted as the result of an unstable gene of feeble penetrance. The conclusion of the genotypic origin of oxycephaly is corroborated by some pedigrees showing a transmission through 2 or more generations. Two reported cases with consanguinity of the parents suggest likewise the possibility of recessive inheritance.The association of oxycephaly with cutis frontis gyrata, as observed in our third case, having not yet been described, we cannot for the moment decide whether this combination is due to chance or whether there exists a pathogenic correlation between both anomalies. |
