Late-onset camptocormia caused by a heterozygous in-frame CAPN3 deletion

Camptocormia is defined by a pathological involuntary flexion of the thoracic and lumbar spine that fully reducible in supine position. Although originally described as manifestation conversion disorder, it more commonly caused wide range neurological diseases, particular movement neuromuscular disorders. We describe here rare case late onset camptocormia autosomal dominant calpainopathy due to heterozygous in-frame deletion CAPN3 leading loss single lysin amino acid catalytic domain calpain-3. Creatine kinase levels, electromyography, thigh muscle MRI were normal. Muscle biopsy did not show lobulated fibers calpain-3 protein expression was decreased, but vitro functional assays showed impaired proteolytic function of. Lys254del CAPN3. Autosomal should be considered differential diagnosis unexplained paravertebral myopathies even presence normal creatine absence fibers, decreased expression, limb involvement.