International collaboration to improve knowledge on myotonic dystrophy type 2.

The TREAT-NMD Global Registry Network is a global collaboration of neuromuscular disease registries, including myotonic dystrophy type 2 (DM2), which aims to facilitate collaborative research and clinical trials. This study aimed to assess DM2 patients included in the network, and to analyse their socio-demographic and clinical features. Data were collected through email surveys sent to 16 TREAT-NMD myotonic dystrophy core member registries. 10 registries enrolled DM2 patients. The total number of DM2 cases was 1,720, with the Czech, German, and USA registries enrolling the most patients (445, 430, and 339 cases, respectively). The highest rates were seen in Czechia and Serbia (4.2 and 2.0 registered per 100,000 population, respectively). High DM2:DM1 ratios were seen in Central Europe. The median age at registry entry was 51 years. Symptom onset occurred before age 20 in 14% of cases. One fifth of patients used an assistive device to walk, and 4% were non-ambulatory. Insertion of a pacemaker or implantable cardioverter-defibrillator was reported in 4% of subjects, while 7% used non-invasive ventilation. This represents the largest DM2 cohort assembled to date, providing demographic and clinical data for future research and trial recruitment, illustrating TREAT-NMD's international reach and the importance of capturing DM2 data.