Manifestations of clinical polymorphism of myotonic dystrophy type 1: the two familial cases

Abstract

Myotonic dystrophy type 1 (DM1) is one of the most common hereditary forms of MD both among adult patients and in pediatric practice. Due to clinical heterogeneity as well as polymorphism of symptoms in different forms of DM1 there is a problem of insufficient detection of this disease. An earlier onset and a more severe course usually suggest maternal inheritance of the disease, as is clearly shown in the first clinical case described in the Article. However, the other described case demonstrates the phenomenon of anticipation that can be traced during the transmission of DM1 on the paternal side, which is not typical for DM1. The two presented clinical cases, in addition to muscle symptoms, demonstrate many manifestations from various organs and systems, including heart rhythm disturbances, respiratory failure, breathing disorders during sleep, cognitive and emotional disorders, early cataracts, diabetes mellitus, gastrointestinal tract dysfunction, orthopedic complications. Focal white matter lesions and cortical atrophy identified by neuroimaging using magnetic resonance imaging in patients from the presented cases were not associated with the presence of neuropsychological disorders. The multisystem nature of manifestations confirms the need for increasing awareness of healthcare specialists about this disease as well as the monitoring of patients with DM1 by a multidisciplinary team of experts.