Allele α(LELY) is a low-expression allele of the erythroid spectrin α- chain that is characterized by a C → G mutation at position α1857 in exon 40 and a C → T (nt -12) mutation in intron 45. This second mutation is probably responsible for the partial skipping of exon 46. This exon is essential for the nucleation of the α-chains by the β-chains during erythropoeisis. Although allele α(LELY) remains asymptomatic in both heterozygotes and homozygotes, it enhances the expression of deleterious α- alleles that occur and, as such, has clinical importance. In this study, the frequency of allele α(LELY) was estimated in two ethnically different Brazilian populations: a random sample of blood donors from Campinas, a city located in Sao Paulo State, in the southeastern region of Brazil, and a sample of Parakana Indians (Tupi tribe), a very isolated population with a high degree of inbreeding. The frequency of allele α(LELY) in the blood donor's sample (n = 54) was 24.1% whereas in the indigenous sample (n = 41), it was 15.9%. These frequencies were not significantly different at the 5% level (χ2 = 1.931). Similarly, when the frequencies of our samples were compared with those of the four ethnic groups studied by Marechal et al. [Br J Haematol 90:553-556, 1995], no significant differences were found at the 5% level (χ2 = 6.686). These results suggest that allele α(LELY) is a very ancient allele since it occurs with a relatively uniform and high frequency in all human ethnic groups studied so far. These findings confirm the importance of allele α(LELY) in influencing the expression of deleterious α-spectrin alleles. To our knowledge, these are the first data concerning allele α(LELY) in native Americans.573212214Alloisio, N., Morlé, L., Maréchal, J., Roux, A.-F., Ducluzeau, M.-T., Guetarni, D., Pothier, B., Delaunay, J., SpαV/41: A common spectrin polymorphism at the αIV-αV domain junction (1991) J Clin Invest, 87, pp. 2169-2177Wilmotte, R., Maréchal, J., Morlé, L., Baklouti, F., Philippe, N., Kastally, R., Kotula, L., Alloisio, N., Low expression allele αLELY of red cell spectrin is associated with mutations in exon 40 (αV/41 polymor phism) and intron 45 and with partial skipping of exon 46 (1993) J Clin Invest, 91, pp. 2091-2096Randon, J., Boulanger, L., Maréchal, J., Garbarz, M., Vallier, A., Ribeiro, L., Tamagnini, G., Delaunay, J., A variant of spectrin low-expression allele alpha LELY carrying a hereditary elliptocytosis mutation in codon 28 (1994) Br J Haematol, 88, pp. 534-540Maréchal, J., Wilmotte, R., Kanzaki, A., Dhermy, D., Garbarz, M., Galand, C., Tang, T.K., Delaunay, J., Ethnic distribution of allele αLELY, a low-expression allele of red cell spectrin α-gene (1995) Br J Haematol, 90, pp. 553-556Curtin, P.D., (1969) The Atlantic Slave Trade: A Census, , Milwaukee: University of Wisconsin PressGibbons, A., Geneticists trace the DNA trail of the 1st Americans (1993) Science, 259, pp. 312-313Black, F.L., Salzano, F.M., Layrisse, Z., Franco, M.H.L.P., Harris, N.S., Weimer, T.A., Restriction and persistence of polymorphisms of HLA and other blood genetic traits in the Parakanã Indians of Brazil (1981) Am J Phys Anthropol, 52, pp. 119-132Saiki, R.K., Geelfond, D.H., Stoffel, S., Scharf, S.J., Higuchi, R., Horn, G.T., Mullis, K.B., Erlich, H.A., Primer-directed enzymatic amplification of DNA with a thermostable DNA polyinerase (1988) Science, 239, pp. 487-491Gallagher, P.G., Forget, B.G., Spectrin St Louis and the αLELY allele (1994) Blood, 84, pp. 1684-1686Saad, S.T.O., Salles, T.S.I., Carvalho, M.H.M., Costa, F.F., Molecular characterization of glucose-6-phosphate dehydrogenase deficiency in Brazil (1997) Hum Hered, 47, pp. 17-21Neel, J.V., Salzano, F.M., Further studies on the Xavante Indians. X. Some hypotheses-generalizations resulting from these studies (1967) Am J Hum Genet, 19, pp. 554-574Chagnon, N.A., (1974) Studying the Yanomamo, , New York: Holt, Reinhart, Winston