NCIt definition : A rare genetic disorder caused by mutations in the TPM3, ACTA1, RYR1 and SEPN1 genes.
It is inherited in an autosomal dominant or recessive pattern and rarely in an X-linked
pattern. It manifests with myopathy throughout the body, particularly in the muscles
of the shoulders, upper arms, hips, and thighs. Affected individuals may have contractures,
lordosis, or scoliosis. In a minority of cases mild to severe breathing problems may
occur.;