Hereditary ectodermal dysplasia presents a syndrome of incomplete development of the epidermis and its appendages and is associated with sweating disturbances, anomalous growth of the nails and teeth, and hypotrichosis. The clinical picture may vary considerably, depending on the degree of development of each of these signs. It has been pointed out that the disease involves not only skin and structures derived from ectoderm, but also organs of mesodermal and endodermal origin.* We have recently studied a case of ectodermal dysplasia which was associated with severe refractory anemia of long duration. As this case affords interesting observations on the problem of hereditary ectodermal dysplasia, as well as primary refractory anemia, a detailed description of the case will be presented. Report of a Case The patient was hospitalized on Dec. 26, 1953, because of abdominal pain, weakness, and fatigability. From his youth he had