LAUSR

A 28-year-old man had spasmodic dysphonia due to focal oromandibular-laryngeal dystonia from the age of 6, evolving rostrocaudally into a particular gait dystonia resembling Charlie Chaplin's Charlot gait (video 1). Recently he developed a progressive worsening of bulbar symptoms and a severe dysarthrophonia. No pyramidal or parkinsonism signs were observed. No intellectual dysfunction was noted. Head MRI was normal. Secondary causes of dystonia were excluded. Dystonia next-generation sequencing panel (58 genes) was negative. The sequencing of KMT2B identified a heterozygous de novo variant c5198-4_5206del(p?)-intron24/exon25, classified as pathogenic. This case expands DYT-KMT2B's clinical phenotype due to early oromandibular-laryngeal involvement and atypical gait dystonia.1,2