RYR1 and congenital myopathy: Early involvement of the sartorius muscle has also been described in patients with mutations in SPEN1 [19], RYR1 [20], TNPO3 [21], and MYH7 [22], in some congenital myopathies like ACTA1 [23], and in myofibrillar myopathies with mutations in DES [24] or CRYAB [12].