Hereditary spherocytosis (HS) is a common hemolytic anemia caused by defects in the erythrocyte membrane proteins. The screening of mutations in the ankyrin‐1 (ANK1) gene of 28 Brazilian HS patients showed two new missense mutations (His276Arg and Ile1054Thr) and one novel promoter mutation (–153 G→A). The His276Arg mutation affected the invariable TPLH sequence on repeat 9. The –153 mutation was linked in cis to the known –108 T→C mutation. In contrast to other populations, we were able to detect mutations in the ankyrin‐1 gene in only 10% of our patients. It is also interesting to point out that, from 15 informative subjects for the 3′ Acn repeats, only one presented a loss of heterozigosity at the cDNA level. Taken together, these results suggest that mutations in the ankyrin‐1 gene might not be as common in Brazil as described for other populations. Hum Mutat 16:529, 2000. © 2000 Wiley‐Liss, Inc.