LAUSR

Mutations in KMT2B were fi rst identi fi ed in individuals with early-onset complex dystonia. 1 Since then, it is emerging as one of the most common causes of genetic childhood-onset dystonia. 2 Additional features include short stature, dysmorphism, developmental delay, psychiatric features, endocrinopathy and others. 3 Patients with DYT- KMT2B refractory generalized dystonia maintain signi fi cant bene fi t from internal globus pallidus deep brain stimulation (GPi-DBS) therapy as previously reported, except for laryngeal dystonia and gait. 3 We wish to contribute our observation of freezing of gait (FOG) in KMT2B related dystonia by reporting fi ve subjects (four females) with protein truncating variants (PTV) (Table 1). Clinical DBS 3 The mean age at dystonia onset was 3.6 years (range: 2 6 years). The median age at DBS implant was 23 years 8 30.3 years), and patients were for a median of 14.5 years (IQR: 8.5 – 24 years) after DBS. the 1, 2, and 3, in all, from 14 43 years of age (range: 1 15.5 years 123 I-io fl upane) in patients undertaken years