Résumé
The prevalences of abnormal hemoglobins and thalassemias depend largely upon the hereditary racial composition and geographic origins of the affected populations. In Central América and Panamá, where the racial and immigration patterns are highly varied, prevalences vary greatly from one country to another and even from one population group to another within a given country. Since literature on this problem is scanty, the review presented draws heavily upon fairly extensive information obtained from Costa Rican studies. Nevertheless, it has been supplemented with whatever data it has been possible to find on Panamá and other Central Américan countries. The sickle cell gene for hemoglobin S (Hb S) has not been found among the racially indigenous groups studied in Costa Rica and Panamá. However noteworthy prevalences of Hb S have been reported among Blacks and other population groups in Costa Rica, El Salvador, Guatemala, Honduras, and Panamá, with the heterozygous Hb S marker reaching a level of 30 per cent of one survey population in the latter country. In addition, the presence of the hemoglobin C marker has been reported in Costa Rica, Honduras, and Panamá; and the sickling syndromes- including heterozygous Hb SC, Hb S combined with Hb Korle-Bu, homozygous Hb S with alpha thalassemia, heterozygous Hb S with alpha (B+) thalassemia and Hb S with beta thalassemia (both B+ and Bo)- have been