HDL2 and Acanthocytosis

The possibility that HDL2 is a form of neuroacanthocytosis emerged in a family studied by Walker et al. prior to the discovery of the HDL2 mutation. All three individuals in the family, clinically described above, had 30-35% acanthocytes as measured both by peripheral blood smears and scanning EM (Fig. 5). RBC membrane extract showed a prominent band not present in a normal control, and consistent with a band 3 breakdown product. Subsequently, peripheral blood smears from three members of a pedigree from Mexico, two members of the index pedigree, and one member of a fourth pedigree were examined [28]. Only one of the individuals from the Mexican family had acanthocytosis (defined as >30% acanthocytes on a

Fig. 5 Acanthocytes in HDL2. (a) Scanning EM of peripheral blood. (b) Band 3 abnormalities in peripheral RBC membranes. MW = molecular weight markers. (Figure and portions of the figure legend, are reprinted with permission from Walker et al. [26].)

peripheral smear). The presence of acanthocytes in two unrelated pedigrees with HDL2 is unlikely to be coincidental. It therefore appears that acanthocytosis is a variably penetrant feature of HDL2, and that mutation of JPH3 may lead to disruption of RBC membranes.

0 0

Post a comment