1. The incidence of Thalassemia minor in the Sikh community of Vancouver, Canada, was computed to be six per cent from a study of 80 individuals, of whom five showed this condition.
2. To determine the incidence in blood relatives, the families of the above five propositi were then studied in detail. In addition, a sixth family, that of the original propositus was included. This made a total of 79 individuals, of whom 38 had Thalassemia minor and none had Thalassemia major.
3. It is suggested that a large pool of the Thalassemia gene existed in the Mediterranean basin and perhaps spread to Italy, Greece, Syria, Kurdistan, India, Thailand and China, countries which lie along the routes of early migration of races.