Abstract
Catalase, a heme-containing antioxidant enzyme, was once considered essential for human survival. It is widely distributed in the human body and is particularly abundant in red blood cells. The term "acatalasemia" first appeared in the Proceedings of the Japan Academy in 1951, drawing global attention to families genetically deficient in catalase. This deficiency not only altered the significance of catalase but also played a pioneering role in human genetics during an era of limited genetic methodology. In this article, we examine the discovery of acatalasemia by an otolaryngologist during surgery on an 11-year-old girl. This remarkable journey led to epoch-making research spanning biochemistry, hematology, and human genetics.