Elliptopoikilocytosis associated with the alpha 469 His-->Pro mutation in spectrin Barcelona (alpha I/50-46b).

We present two Spanish children with hereditary elliptopoikilocytosis. The mother displayed a symptomless elliptocytosis. Spectrin maps showed the alpha I/50-46b abnormality in the mother and in the children. The change was more conspicuous in the children than in the mother. The father carried the alpha V/41 allele, which is a common allele endowed with low expression. The alpha V/41 allele was also present in the children accounting for the much more severe expression of the alpha I/50-46b variant. The responsible mutation yielding the latter appeared to be the alpha 469 His-->Pro substitution (CAT-->CCT), which is a novel abnormality. The corresponding spectrin was designated spectrin Barcelona. As is often the case in hereditary elliptocytosis or poikilocytosis related to alpha-spectrin variants, the change involved a helix 3; namely, helix 3 of repeating segment alpha 5.