Objective: To summarize the clinical phenotype and genotypic characteristics of 3 patients with KBG syndrome and epileptic seizure.
Methods: Clinical data of the patients were collected. Family-trio whole exon sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing.
Results: Patients 1 and 2 were boys, and patient 3 was an adult woman. All patients had epileptic seizures and mental deficiency. Their facial features included triangular face, low hair line, hypertelorism, large forward leaning auricles, broad nasal bridge, upturned nostrils, long philtrum, arched upper lip, and macrodontia. The two boys also had bilateral Simian creases. WES revealed that the three patients all harbored heterozygous de novo frameshift variants in exon 9 of the ANKRD11 gene including c.2948delG (p.Ser983Metfs*335), c.5397_c.5398insC (p.Glu1800Argfs*150) and c.1180_c.1184delAATAA (p.Asn394Hisfs*42). So far 291 patients with ANKRD11 gene variants or 16q24.3 microdeletions were reported, with over 75% being de novo mutations.
Conclusion: Above findings have enriched the spectrum of ANKRD11 gene mutations underlying KBG syndrome. WES is helpful for the early diagnosis of KBG, and provided reference for genetic counseling of this disease.