• The retrospective study involves 72 participants (34 men and 38 women) with LGMD R1 (calpainopathy).
• Patients have the following characteristics:
- the disease manifests between one and 35 years, on average around 13 years,
- nearly 40% of the participants had manifestations before the age of 12, 49% between the ages of 12 and 20, and 11% after the age of 20,
- the first symptoms are progressive proximal weakness of the upper (67%) and lower (52%) limbs, tiptoe walking (21%) and difficulty running quickly (10%),
- 50% of patients reported recurrent falls.
• At consultation, patients had:
- Difficulty getting up and climbing stairs for 97% of them,
- signs of scapula detachment in 70%,
- contractures in 58%.
• Ten years after the onset of symptoms, the majority of participants had maintained walking and none showed signs of respiratory distress.
• 19 novel genetic mutations were identified within the CAPN3 gene, among the 47 mutations of the gene distinguished in the 72 patients. Missense mutations lead to less severe forms of the disease, compared to other types of mutations.
