Spα1/65 hereditary elliptocytosis in North Africa

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Abstract
The Spα1/65 variant of the spectrin has been recently described in black people with hereditary elliptocytosis (HE). The present study reports on a similar Spα1/65 variant in nine North African persons belonging to four unrelated families. The abnormality was associated with a variable degree of elliptocytosis. In one case, red cell morphology was normal. In the nine carriers of the biochemical abnormality, the spectrin dimer self‐association was defective. The association constant was reduced: 0.65 to 1.7 × 105 M−1 (controls: 4.6 × 0.5 × 105 m M−1 (n = 21)); in six cases, there was a higher level of spectrin dimer in the low ionic strength extract at 4°C: 13.0 to 19.7% (controls: 6.4 ± 2.1% (n = 7)). Limited tryptic digests of spectrin from the nine persons revealed a decrease of the 80,000‐dalton α‐1 domain, and the concomitant appearance of a peptide with a molecular weight of 65,000 daltons and an isoelectric point ranging from 5.0 to 5.1. There was a correlation between the proportion of the 65,000‐dalton fragments, the defect of spectrin self‐association, and the extent of morphological alteration. This is the first large series concerning a spectrin abnormality in non‐black persons. In North Africa, cases of HE that are not due to a protein 4.1 defect have turned out so far to be associated with the Spα1/65 variant.