The Diego Blood Factor

Abstract

IN 1953 a new low-incidence blood factor, Diego or Di^a, responsible for hæmolytic disease, was described with the aid of an antibody produced by a mother living in Caracas, Venezuela^1,2, The antibody, anti-Di^a, reacted with the blood of the affected child (propositus) and two of the three siblings of generation IV. The blood factor was also present in the father and three of his six siblings of generation III. The factor was transmitted to them by the paternal grandmother (generation II) of the propositus, who received it from her mother of generation I. The factor was present in the blood of nine out of twenty-nine members of the Diego family tested.