This study aims to examine the clinical characteristics, diagnostic delays, and associated comorbidities of DM2 patients treated at a single center.

Myotonic Dystrophy Type 2 (DM2) is an autosomal dominant, multisystem disease with highly variable clinical presentation.

The study included 17 patients (6 males, 11 females) with a mean age at diagnosis of 63.4 years. A positive family history of DM2 was reported in 53% of cases. The average time to diagnosis was 5.9 years.

Proximal muscle weakness was the most common presenting symptom (70.6%), while only one patient initially presented with myotonia. Electromyography (EMG) was performed on 12 patients, revealing myotonia as the most frequent abnormal finding, followed by complex repetitive discharges and fibrillations. Most patients had normal motor unit potentials, though two showed myopathic motor units. Additionally, 87.5% of the patients had normal CK level.

Brain MRI was done in 10 out of the 17 patients. Non-specific white matter lesions were found in in 50% of patients, and 30% showed brain atrophy. Cardiac involvement was documented in four patients, five had type 2 diabetes, and four had other endocrine disorders. Cataracts was diagnosed in 76% of patients, with a mean age of diagnosis of 53 years. Obstructive sleep apnea (OSA) was identified in six out of seven patients with available sleep studies, and cancer was diagnosed in 53%.

DM2 has a wide spectrum of clinical presentation and can be a diagnostic challenge. It should be considered in any patient with proximal weakness or in the presence of myotonic discharges on EMG.