β-Thalassaemia in Cubans: Novel allele increases the genetic diversity at theHBB locus in the Caribbean
2000; Wiley; Volume: 64; Issue: 1 Linguagem: Inglês
10.1002/(sici)1096-8652(200005)64
ISSN1096-8652
AutoresAdriana Muñiz, Gisela Martı́nez, João Lavinha, Paula Pacheco,
Tópico(s)Food Security and Health in Diverse Populations
ResumoIn order to establish the molecular basis of β-thalassaemia in Cubans, a total of 75 unrelated individuals, with β-thalassaemia major (7), Hb S-β-thalassaemia (28), Hb C-β-thalassaemia (1), and β-thalassaemia trait (39) yielding 82 β-thalassaemia alleles, were analyzed. Seventeen different point mutations were identified accounting for 93% of the β-thalassaemia alleles studied, revealing a high genetic heterogeneity at the HBB locus in this population. The more prevalent mutations, namely, CD 39 (C → T) (30.5%), −29 (A → G) (13.4%), IVS-I-110 (G → A) (8.5%), and IVS-II-1 (G → A) (8.5%), reflect the Mediterranean and African predominant ancestry of the extant Cuban population. We also report the identification of a novel allele, IVS-I-108 (T → C), that possibly activates a cryptic branch site, in a β-thalassaemia carrier with no other molecular defect within the β-globin gene and its proximal promoter. This study shows that prenatal diagnosis of β-thalassaemia should be feasible in about 60% of at-risk pregnancies by direct detection of selected point mutations. However, due to the wide spectrum of mutations, and in order to offer fully informative prenatal diagnosis to more than 87% of at-risk couples, the screening for β-thalassaemia mutations in Cubans should be performed by using a general point mutation detection method, such as DGGE (denaturing gradient gel electrophoresis). Am. J. Hematol. 64:7–14, 2000. © 2000 Wiley-Liss, Inc.
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