Hb Evans or alpha 262(E11)Val----Met beta 2; an unstable hemoglobin causing a mild hemolytic anemia

Structural analysis of the alpha chain of the hemoglobin from a Caucasian female with a mild hemolytic anemia showed the presence of a variant with a Val----Met substitution at position alpha 62. The valine at this position forms one of the contacts with heme and its replacement by methionine will likely decrease heme binding and cause a distortion of the heme crevice and a decreased stability of the abnormal protein. Dot-blot analysis of amplified DNA with 32P-labeled synthetic oligonucleotide probes confirmed the suspected G----A mutation in the first position of codon 62, and also located the mutation in the alpha 2-globin gene. The mutation was found in the proposita and one of her daughters but was most probably absent in her parents.