Distinct whole-body muscle MRI imaging patterns in PAX7-congenital myopathy: A case report.

PAX7 is a myogenesis transcription factor important for satellite cell specification and function and thus involved in muscle growth, maintenance, repair and regeneration. Recently, a new autosomal recessive congenital myopathy was described that is caused by biallelic variants in PAX7. Our aim is to describe phenotype and whole-body muscle MRI with follow-up imaging findings in a patient with a novel homozygous missense variant in PAX7. We also compare our patients' imaging features with a patient reported in the initial study, to identify a possible emerging pattern for PAX7-congenital myopathy. Generalized muscle hypotrophy and selective sternocleidomastoid, paraspinal and thigh muscle involvement emerge as suggestive findings and could serve as a recognizable fingerprint to differentiate early-onset myopathies within the emerging group of 'primary satellite cell-opathies'.