BACKGROUND: KBG syndrome is a monogenic disorder caused by heterozygous pathogenic variants in ANKRD11. A recent single-case study suggested that the clinical spectrum of KBG syndrome, classically defined by distinctive craniofacial traits and developmental delay, may include movement disorders. CASE REPORT: We report a 24-year-old patient harboring a pathogenic de novo ANKRD11 frameshift variant. The phenotype was dominated by a progressive tremor-dominant movement disorder, characterized by rest, intention and postural tremor of the hands, voice tremor, head and tongue tremor, increased muscle tone and signs of ataxia. Additionally, the patient had a history of mild developmental delay and epilepsy. DISCUSSION: Adding to the recently described individual, our present patient highlights the relevance of movement disorders as a clinically relevant manifestation of KBG syndrome. ANKRD11 pathogenic variants should be considered in the differential diagnosis of combined tremor syndromes.
FörderungenElse Kroner-Fresenius-Stiftung European Joint Programme on Rare Diseases German Federal Ministry of Education and Research (BMBF, Bonn, Germany) Federal Ministry of Education and Research (BMBF) Free State of Bavaria under the Excellence Strategy of the Federal Government Lander Technical University of Munich - Institute for Advanced Study German Research Foundation (DFG)