A Chinese patient with KBG syndrome and a 9q31.2-33.1 microdeletion.

KBG syndrome is characterized by postnatal short stature, macrodontia, facial and hand anomalies, delayed bone age and intellectual disability. KBG syndrome is an infrequently reported autosomal dominant condition caused by a mutation or haploinsufficiency of ANKRD11 at 16q24.3. We report on a patient, who showed many manifestations of KBG syndrome and was found to harbor a de novo ANKRD11 mutation, c.362T > A (p.Met121Lys). As the patient showed additional characteristics not occurring in KBG syndrome, a CGH array was performed which showed a de novo microdeletion of 9q31.2-q33.1. The majority of findings in our patient can be explained by the combined ANKRD11 mutation and 9q31.2-33.1 deletion. The case demonstrates well the need for comparing an abnormal genotype with a detailed phenotype analysis and the need for further studies in case the phenotype is unusual for the genotype.