<i>MECP2</i> Duplication Syndrome

Since the initial report that clearly established a causal role between duplication of the MECP2 gene and a severe syndromic form of intellectual disability, many new patients have been identified and reported, and the etiology in already published families solved. This has led to the establishment of a clinically recognizable disorder. Here, we review the clinical data of 129 reported and nonreported male patients with MECP2 duplication syndrome.