[Hereditary stomatocytosis of the hydrocytosis type: a report of one family and red cell membrane studies].

A case of hereditary stomatocytosis with hemolytic anemia, increased autohemolysis, increased osmotic fragility, and shortened erythrocyte survival is reported. The erythrocytes were abnormally permeable to sodium and potassium; the sodium concentration of the erythrocytes was high, and the potassium level was low. This case was different from the first reported Japanese case of hereditary stomatocytosis of the hydrocytosis type in the Na(+)-K+ ATPase and Mg+ ATPase activity. In the first reported Japanese case, these activities were within normal limits, but in this case, they were increased. The findings indicate that membrane transport in hereditary stomatocytosis of the hydrocytosis type may vary from case to case.