The chromosome 17q21.31 microdeletion syndrome has been renamed. The condition is now called the Koolen de Vries syndrome (KdVS; MIM #610443). The syndrome is caused by either the fact that a small part of chromosome 17 is missing (17q21.31 microdeletion) or a defect in a single gene: the KANSL1-gene.
The syndrome is a multisystem disorder characterized by developmental delay, intellectual disability, muscle weakness (hypotonia), epilepsy, distinctive facial features and congenital malformations of the heart, urogenital tract and the central nervous system. Not all individuals with KdVS have all these features, i.e., the clinical spectrum of the condition is wide.
At the Department of Human Genetics, Radboud university medical centre, we have developed a clinical survey, allowing parents to submit clinical data in a systematic way. This will allow the development of specific management protocols.
David A. Koolen (Nijmegen, the Netherlands), Evan E. Eichler (Seattle, US).
Questions or enquiries should be directed to David A Koolen. Contact