Historical note: the extraordinary handless and footless families of Brazil - 50 years of acheiropodia.

The history of acheiropodia is divided into 4 phases: discovery, exploration, modern studies, and contemporary knowledge. The discovery phase (1929-1930) is represented by the publication of the 1st family. For about 30 years, it remained the only family referred to in a number of textbooks of medicine, biology, and others. In the exploration phase (1956-1966), the first family was reanalyzed, other families were ascertained and analysed, and some radiologic aspects of the anomaly were published. The modern phase (1968-1972) is characterized by a large series of studies on the clinical aspects of acheiropodia, including laboratory and radiological examinations, psychological tests, status of vision, electrocardiograms, etc. In the contemporary phase (since 1974), genetic aspects prevailed, and studies were published on segregation analysis, selection pressure, genetic load, mutation rate, etc. Each one of these 4 phases is analyzed in detail.