Instability of red cell shape associated with the absence of membrane glycophorin C

Erythrocytes from 3 Gerbich-negative siblings readily converted to echinocytes when subjected to changing concentrations of sodium or lithium chloride. When erythrocyte membrane proteins were assayed by immunoblotting with human anti-Ge 1,2, normal membranes were found to contain a reactive component of an approximate molecular weight of 33,000 daltons which was absent from the Gerbich-negative individuals. PAS staining and mobility on SDS gels identified this component as glycophorin C. These observations indicate that glycophorin C (beta-sialoglycoprotein) is a component of the Gerbich antigen and is involved in normal cell shape maintenance.