The first antenatal diagnosis of KBG syndrome: a microdeletion at chromosome 16q24.2q24.3 containing multiple genes including ANKRD11 associated with the disorder

KBG syndrome was first described by Herrmann 1 and is associated with distinct dental, craniofacial, neurobehavioral, and skeletal anomalies, macrodontia of the upper central incisors of the permanent teeth being the dominant diagnostic feature 2. Whole‐exome sequencing (WES) of affected individuals has recently identified mutations in ANKRD11 as causative of the disorder 2. KBG syndrome can occur due to various loss of function alterations in ANKRD11, or as a result of known 16q24 microdeletions encompassing ANKRD11. ANKRD11 encodes ankyrin repeat domain 11, which interacts with nuclear receptor complexes to alter transcription localizing to the nuclei of neurons, accumulating in discrete inclusions in neurons, thus supporting the role of ANKRD11 in neural plasticity 3. Diagnosis of KBG syndrome is possible in the neonatal period; however, the clinical signs can manifest mildly with few associated medical complications and as such diagnosis can be entirely missed or delayed. More often, diagnosis is made at 7–8 years of age following eruption of the upper permanent central incisors. Hence, it is suspected that KBG syndrome is an underdiagnosed condition.