The Natural History of Patients With Mutations in SEPN1 (SELENON) or LAMA2

SEPN1 (SELENON) is a rare congenital myopathy due to mutations in the SELENON gene. MDC1A is a rare congenital muscle dystrophy due to mutations in the LAMA2 gene. Currently, not much is known about the natural history of these two muscle diseases and no (curative) treatment options exist. The investigators aim to study the natural history of SELENON- and LAMA2-related myopathy/congenital muscular dystrophy patients and prepare for future trials by selection of the most appropriate outcome measures. To this end, a standard medical history, neurological examination, functional measures, questionnaires, cardiac examination, respiratory function tests, radiological examination and accelerometry will be performed over an one and-a-half year period.