"Case Report: Klinefelter Syndrome Presenting With Dystonic Tremor: Expanding the Phenotypic Spectrum and Therapeutic Option".

[BACKGROUND] Klinefelter syndrome (KS) is associated with tremor and dystonia, but the exact phenomenology and neurophysiology are not well described.

[CASE REPORT] We present a case of a 51-year-old married male who presented with segmental dystonia affecting the bilateral upper limbs and lower face, accompanied by perioral dyskinesia and a dystonic tremor that was more pronounced on the left side. There was no family history of similar symptoms. His evaluation revealed a history of infertility and the presence of gynecomastia, prompting further endocrine assessment, which demonstrated hypergonadotropic hypogonadism. This finding guided the diagnosis of Klinefelter syndrome (KS), confirmed by a 48,XXY karyotype. He was treated with antitremor medications and Botulinum toxin (BoNT-A), which led to moderate improvement.

[DISCUSSION] Our case represents the fourth reported case of KS with dystonic tremor in the literature.