A retrospective international study coordinated by a team from the Myology Centre for Research at the Institute of Myology was conducted to describe the natural history of an early-onset form of laminopathy: congenital muscular dystrophy linked to the LMNA gene. Thus, data from 151 patients with laminopathy who presented with muscle symptoms that appeared before the age of two were collected in 34 centres in 14 countries (mainly France, China and the United Kingdom) and analyzed.
The results of this first natural history study involving such a large number of patients confirm the progressive course of the disease, especially between the ages of 5 to 15 years. First occur motor symptoms, followed by respiratory, gastrointestinal, orthopedic and cardiac symptoms. The authors of this study also compared two subgroups of patients, ambulant or non ambulant. The results show that non ambulant have:
- a significantly earlier age of onset and death, with symptoms that evolve more rapidly, particularly at the motor, then respiratory and cardiac level,
- an earlier age of initiation of non-invasive ventilation.
The authors also showed that the most common mutation in this form of laminopathy, the p.Arg249Trp variant of the LMNA gene, is responsible for a more severe form of the disease. Patients with this mutation never acquire walking or lose it very quickly and have early respiratory involvement. These results will be of great interest for the establishment of future clinical trials in this form of laminopathy.