Patients with calpainopathy typically have normal early motor milestones (i.e., walking age), but signs of muscle deterioration can be detected by elevated creatine kinase (CK) levels in the blood. Early signs often include:
- a “waddling” gait
- walking on tiptoes
- scapular winging (shoulder blades protrude from the back)
- difficulty climbing stairs
Some patients also report fatigue or muscle pain as early symptoms. Calpainopathy affects large muscles the most, and results in both weakness and reduced exercise endurance. About half of patients experience muscle contractures, which may cause toe-walking and reduced range of motion.
Eventually, patients have difficulty with daily living activities such as climbing stairs, rising from a chair, or getting up off the floor. Patients typically lose their ability to walk within 10-30 years from the first onset of symptoms, although this varies greatly from person to person. LGMDD4 tends to be associated with a later onset and more slowly progressive symptoms than LGMD2A/R1.
Unlike some other forms of muscular dystrophy, heart and lung involvement is fortunately rare, and life expectancy may be near normal. Calpainopathy does not affect muscles in the face or cause intellectual impairment or behavioral disorders.
You may find the TREAT-NMD Limb-Girdle Muscular Dystrophy Guide for Families, Caregivers & HCPs to be a helpful resource to learn more about LGMD.