STAC3, a gene encoding a small adapter protein, is essential for excitation-contraction (EC) coupling in skeletal muscles. It functions as a key component in this process, interacting with the voltage-sensor CaV1.1, and is involved in regulating calcium-related signaling pathways [2,4,6]. Its role in muscle development and function makes it biologically significant, and genetic models can provide insights into its functions.

In terms of disease-related findings, STAC3 has been associated with congenital myopathies. A homozygous missense variant (c.851G > C; p.Trp284Ser) in STAC3 is linked to Bailey-Bloch congenital myopathy, also known as Native American myopathy (NAM), which is characterized by congenital weakness, arthrogryposis, cleft palate, and other symptoms [1]. This variant has been identified in non-Native American patients as well, such as those from the Comoros Islands and Southern African patients with congenital hypotonia [1,3]. In addition, in vitro experiments on C2C12 myoblasts and Stac3 knockout mouse embryos suggest that Stac3 inhibits myoblast differentiation into myotubes, which may be important for proper skeletal muscle development [5].

In conclusion, STAC3 is crucial for skeletal muscle EC coupling and muscle development. Research using genetic models, especially knockout mouse models, has revealed its role in congenital myopathies and myoblast differentiation. Understanding STAC3's functions provides insights into the mechanisms of muscle-related diseases and muscle development processes.