Clinical score for early diagnosis of myotonic dystrophy type 2

Ivanović Vukan; Perić Stojan; Pesović Jovan; Tubić Radoje; Božović Ivo; Petrović Djordjević Ivana; Savić-Pavićević Dusanka; Meola Giovanni; Stojanović Rakočević Vidosava

doi:10.1007/s10072-022-06507-9

Published November 19, 2022 | Version v.1

Journal article Open

Clinical score for early diagnosis of myotonic dystrophy type 2

1. University of Belgrade - Faculty of Medicine, University Clinical Center of Serbia - Neurology Clinic, Dr. Subotic Street, 11 000, Belgrade, Serbia.
2. University of Belgrade - Faculty of Medicine, University Clinical Center of Serbia - Neurology Clinic, Dr. Subotic Street, 11 000, Belgrade, Serbia. stojanperic@gmail.com.
3. University of Belgrade - Faculty of Biology, Center for Human Molecular Genetics, Belgrade, Serbia.
4. Institute of Oncology and Radiology of Serbia, Belgrade, Serbia.
5. University of Belgrade – Faculty of Medicine, University Clinical Center of Serbia – Neurology Clinic, Dr. Subotic Street, 11 000, Belgrade, Serbia
6. University of Belgrade – Faculty of Medicine, University Clinical Center of Serbia – Cardiology Clinic, Belgrade, Serbia
7. University of Belgrade – Faculty of Biology, Center for Human Molecular Genetics, Belgrade, Serbia
8. Department of Neurorehabilitation Sciences - Casa Di Cura del Policlinico, Department of Biomedical Sciences for Health, University of Milan, Milan, Italy

Abstract Introduction Myotonic dystrophy type 2 (DM2) is a rare, multisystemic, autosomal dominant disease with highly variable clinical presentation. DM2 is considered to be highly underdiagnosed. Objective The aim of this study was to determine which symptoms, signs, and diagnostic fndings in patients referred to neurological outpatient units are the most indicative to arouse suspicion of DM2. We tried to make a useful and easy-toadminister clinical scoring system for early diagnosis of DM2-DM2 early diagnosis score (DM2-EDS). Patients and methods Two hundred ninety-one patients with a clinical suspicion of DM2 were included: 69 were genetically confrmed to have DM2, and 222 patients were DM2 negative. Relevant history, neurological, and paraclinical data were obtained from the electronic medical records. Results The following parameters appeared as signifcant predictors of DM2 diagnosis: cataracts (beta=0.410, p<0.001), myotonia on needle EMG (beta = 0.298, p < 0.001), hand tremor (beta = 0.211, p = 0.001), positive family history (beta=0.171, p=0.012), and calf hypertrophy (beta=0.120, p=0.043). In the fnal DM2-EDS, based on the beta values, symptoms were associated with the following values: cataracts (present 3.4, absent 0), myotonia (present 2.5, absent 0), tremor (present 1.7, absent 0), family history (positive 1.4, negative 0), and calf hypertrophy (present 1.0, absent 0). A cutof value on DM2-EDS of 3.25 of maximum 10 points had a sensitivity of 84% and specifcity of 81% to diagnose DM2. Conclusion Signifcant predictors of DM2 diagnosis in the neurology outpatient unit were identifed. We made an easy-toadminister DM2-EDS score for early diagnosis of DM2.

Notes

FUNDING: The publication fees will be paid by FMM – Fondazione Malattie Miotoniche. GM was supported by FMM-Fondazione Malattie Miotoniche, Milan, Italy Data availability: Raw data were generated at Neurology Clinic, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia. The data that support the findings of this study are available from the corresponding author upon reasonable request.

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