- Mutations in the gene-encoding SERCA1, the fast-twitch skeletal muscle sarcoplasmic reticulum Ca2+ ATPase, are associated with Brody disease. Odermatt, A., Taschner, P.E., Khanna, V.K., Busch, H.F., Karpati, G., Jablecki, C.K., Breuning, M.H., MacLennan, D.H. Nat. Genet. (1996)