Double heterozygosis for hemoglobin C-beta thalassemia: description of a Spanish family. Hemoglobin C-beta thalassemia in a Spanish family.

A spanish family is described with two abnormal genes: 1) hemoglobin C in heterozygosis with normal hemoglobin, introduced by the subject's mother, and 2) heterozygotic betathalassemia for which the father is a carrier. In the subject and his sister, both abnormal genes coincide with the presence of hemoglobin C and hemoglobin F, simulating homozygosis for hemoglobin C. The clinical condition shows medium intensity chronic hemolysis. In the subject's brother, mother and grandmother, simple heterozygosis of hemoglobins A-C is seen, with no apparent clinical manifestations. The father shows subjaundice with some acute hemolytic episodes. Hypotheses are discussed which might explain the presence of these hemoglobins in Spain.