Mirror-image asymmetry in monozygotic twins with kabuki syndrome.

[kabuki syndrome]

Kabuki syndrome (OMIM 147920 ) is a rare disorder characterised by moderate intellectual disability , growth retardation , microcephaly and characteristic facial dysmorphic features which comprise long palpebral fissures , eversion of the lateral third of the eyelids and arched eyebrows with lateral sparseness . Mutations in MLL 2 are the most frequent cause of this disorder . More than 100 MLL 2 point mutations have been reported , but large intragenic deletions comprising one or more exons have not yet been identified . We report on a pair of monozygotic twin brothers in whom a deletion of 2 neighbouring exons was detected . The twins had the characteristic facial features of Kabuki syndrome , and they suffered from microcephaly , cleft lip and palate and congenital heart disease . Cleft lip and palate were left-sided in the first twin and right -sided in the second twin , i .e . they represented a mirror -image asymmetry . The intragenic deletion in these brothers broadens the spectrum of MLL 2 mutations , and they provide a rare example of mirror -image asymmetry of congenital malformations in monozygotic twins .