An inherited anomaly of human eosinophils and basophils.

Inclusions staining gray or blue-gray in Romanowsky treated films were found in eosinophils and basophils in a family as an autosomal dominant anomaly without overt clinical effects. Associated with the inclusions were distinctive crystals which were different from the crystalloids of eosinophil granules and from Charcot-Leyden crystals. The restriction of the anomaly to eosinophils and basophils indicates that these are related more closely to each other than to neutrophils and mast cells, and suggests the existence of a separate stem cell for eosinophils and basophils.