- Mutations in the clathrin-assembly gene Picalm are responsible for the hematopoietic and iron metabolism abnormalities in fit1 mice. Klebig, M.L., Wall, M.D., Potter, M.D., Rowe, E.L., Carpenter, D.A., Rinchik, E.M. Proc. Natl. Acad. Sci. U.S.A. (2003)