Enostosis in a patient with KBG syndrome caused by a novel missense ANKRD11 variant

KBG syndrome (KBGS-OMIM:#148050) is a rare autosomal dominant disease characterized by short stature, intellectual disability, characteristic facies, skeletal anomalies and macrodontia that most commonly affect the permanent upper central incisors. In 2011, Sirmaci et al. (2011) identified heterozygous loss-of-function variants in the ANKRD11 gene on chromosome 16q24.3. So far, more than 150 patients have been reported in the literature. ANKRD11 gene encodes ankyrin repeat domain-containing protein 11 that regulates transcriptional activation (Zhang et al., 2004). Apart from single-nucleotide variations in the ANKRD11 gene, copy number variations on chromosome 16q24.3 can also cause KBG syndrome-like phenotype. In this study, we present a patient with de-novo novel missense variant in ANKRD11 gene. We have also identified skeletal bone enostosis as an additional finding, which is not previously reported.