MYH2 encodes myosin heavy chain IIa, a critical component of the thick filament in skeletal muscle that functions as an actin-based motor protein with ATPase activity essential for muscle contraction 1. As a type IIa myosin isoform expressed in adult limb skeletal muscle, MYH2 plays a fundamental role in muscle filament sliding and sarcomeric organization through its interaction with actin filaments and involvement in the myosin II complex 1. Mutations in MYH2 cause hereditary myosin myopathies characterized by variable phenotypes, including congenital joint contractures and external ophthalmoplegia, with disease severity ranging from mild childhood-onset weakness to progressive adult-onset muscle dysfunction affecting proximal muscles and ambulation 1, 2. Specific missense mutations, such as V970I and L1061V located in the MyHC subfragment 2, affect highly conserved residues and are associated with familial myopathy presenting with muscle weakness and myalgia 3. The strong selective pressure against MYH2 mutations in normal populations suggests that this gene is critical for proper muscle function 3. MYH2 has been identified as a potential biomarker in disease progression models and immune-related conditions affecting multiple tissues 4, 5. MYH2 mutations represent an important consideration in the differential diagnosis of hereditary myopathies and congenital myopathy with ophthalmoplegia.