Hb Calais [beta76(E20)Ala --> Pro]: a family study of a variant with decreased oxygen affinity.

Secondary to the detection of a chronic anemia with a slightly increased Hb F level in a 7-year-old boy carrying a hemoglobin (Hb) variant, we investigated the members of his family and found that they were related to the original case of Hb Calais. In the present study, we report the clinical and biological impacts of this Hb variant in various members of three generations of this family.