NONSENSE MUTATION IN THE ERYTHROCYTE BAND-3 GENE ASSOCIATED WITH DECREASED MESSENGER-RNA ACCUMULATION IN A KINDRED WITH DOMINANT HEREDITARYSPHEROCYTOSIS

We studied a French kindred with typical hereditary spherocytosis (HS) . Studies of erythrocytes and erythrocyte membranes from HS individual s revealed abnormal erythrocyte membrane mechanical stability as well as a 15-20% deficiency of band 3, the anion transporter. Anion transpo rt studies of red cells from two affected individuals revealed decreas ed sulfate flux. Nucleotide sequence of cDNA encoding the distal third of the cytoplasmic domain and the entire transmembrane domain of band 3 obtained by RT-PCR of reticulocyte RNA of an affected family member was normal, Sequence analysis of genomic DNA from an HS individual id entified a nonsense mutation of the band 3 gene, Q330X, near the end o f the band 3 cytoplasmic domain, This mutation was present in genomic DNA of all HS family members and absent in DNA of unaffected family me mbers. Using an RT-PCR-based assay, a marked quantitative decrease in accumulation of the mutant band 3 RNA was detected. Thus the codon 330 nonsense mutation is responsible for the decreased accumulation of mu tant band 3 RNA and the deficiency of band 3 protein in this kindred, These results have important implications for the role of band 3 defec ts in the membrane pathobiology of HS as well as for the techniques us ed in detection of HS mutations.