Hereditary juvenile cobalamin deficiency caused by mutations in the intrinsic factor gene.
Tanner SM, Li Z, Perko JD, Oner C, Cetin M, Altay C, Yurtsever Z, David KL, Faivre L, Ismail EA, et al. Proc Natl Acad Sci U S A. 2005 Mar 15; 102(11):4130-3. Epub 2005 Feb 28.