Interrupted/bipartite clavicle as a diagnostic clue in Kabuki syndrome

Kabuki syndrome is a rare developmental disorder characterized by typical facial features, postnatal growth deficiency, mild to moderate intellectual disability, and minor skeletal anomalies. It is caused by mutations of the KMT2D and KDM6A genes while recently RAP1A and RAP1B mutations have been shown to rarely contribute to the pathogenesis. We report two patients' presentation of Kabuki syndrome caused by different KMT2D mutations, both including an interrupted/bipartite clavicle. The clinical diagnosis of Kabuki syndrome may be challenging, especially in younger patients and we suggest that the observation of a bipartite clavicle may be an additional diagnostic clue to prompt investigation for Kabuki syndrome. We also hypothesize that bipartite/pseudofractured clavicles or other skeletal defects may be under-recognized features of the clinical presentation of the chromatin remodeling disorders.