1.9 Mb microdeletion of 21q22.11 within Braddock–Carey contiguous gene deletion syndrome region: Dissecting the phenotype

AbstractBraddock–Carey syndrome is characterized by Pierre Robin sequence, agenesis of the corpus callosum, facial dysmorphisms, developmental delay, and congenital thrombocytopenia. Recently, Braddock–Carey syndrome was demonstrated to be caused by chromosomal microdeletion in 21q22 including the RUNX1 gene, whose haploinsufficiency is responsible for thrombocytopenia phenotype. Therefore, the syndrome has emerged as a contiguous gene deletion syndrome. Here, we describe an infant with Pierre Robin sequence, facial anomalies, congenital heart defects, hypotonia, and the absence of thrombocytopenia, who was found to have a 1.9 Mb microdeletion within the Braddock–Carey contiguous deletion syndrome region. This deletion spares the RUNX1 gene, narrowing the genomic region responsible for a part of the Braddock–Carey syndrome phenotype. Further studies are awaited to understand the role of the genes located within 21q22 in the pathogenesis of Braddock–Carey syndrome. © 2012 Wiley Periodicals, Inc.