Low factor XII level in an individual with Sotos syndrome

Sotos syndrome is an overgrowth disorder that manifests characteristic dysmorphic features, neurological problems, and an increased risk for cancers and heart defects. Alterations of NSD1 are responsible for this disease. A subset of cases arise from deletions, which is of interest as the factor XII locus lies in close proximity to NSD1. This case report describes an individual with Sotos syndrome and factor XII deficiency, providing a potential link between these two genes and, consequently, expanding the clinical phenotype of Sotos syndrome.