Hereditary Spherocytosis (HS) has been localized to either chromosome 8 or 12 and has been shown to belong to the Gm-Pi Linkage group. It is the purpose of this project to clarify the chromosomal localization by the study of linkage of Gm and Pi in families with structural rearrangements of chromosomes 8 or 12, or with heretible Peptidase B or Glutathione reductase variants. Families with HS will be studied to confirm the Gm linkage and to investigate the possibility of heterogeniety. Linkage studies of the Rh-unlinked type of Hereditary Elliptocytosis (E112) and other less well characterized dominant hemolytic anemias will be carried out in an effort to determine, at the minimum, if E112 is in the same linkage group, and therefore, possibly allelic with HS.