NOS1 and myopathy: For example, variations in other genes associated with core myopathies or known to be RyR1 interactors (i.e. FKBP1B, TRDN, ASPH, FKBP1A, STAC3, CACNA1S, CACNA1C, CACNA1A, NOS1, CALM1) or even other unknow genes may present single nucleotide polymorphism that cause subtle modification on the protein product but sufficient to modify the phenotype.