A further report of Brachmann-de Lange syndrome in two sibs with normal parents.

We report on a family in which a girl and a boy in the same sibship show variable manifestations of a less severe type of Brachmann-de Lange syndrome without significant prenatal growth deficiency and reduction deformities of the forearms. Both parents are healthy and phenotypically normal, and no other family members are affected. All the affected sibs except one described so far with normal parents presented the severe type of Brachmann-de Lange syndrome (now sometimes classified as type I: "classic" or "full" Brachmann-de Lange syndrome), with major upper limb anomalies, severe growth and mental retardation and, frequently, early death. We discuss the possible role of genomic imprinting in the etiology of this syndrome.