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Three novel alpha-globin variants were found during a screening program for hemoglobinopathies in blood donors at the UNICAMP Hematology and Hemotherapy Center, Campinas, State of São Paulo, Southeastern Brazil. They were named for the town of origin of the carrier as Hb Itapira [alpha30(B11)Glu-->Val], Hb Bom Jesus da Lapa [alpha30(B11)Glu-->Ala] and Hb Boa Esperança [alpha16(A14)Lys-->Thr]. Hb Itapira, like Hb Bom Jesus da Lapa, shows an electrophoretic mobility similar to that of Hb S [beta6(A3)GluVal, GAG-->GTG] at alkaline pH; it is associated with a triplicate alpha-globin allele (alphaalphaalpha(anti 3.7)) and corresponds to only 5.5% of the total hemoglobin (Hb). Hb Boa Esperança, found in two different individuals, moves faster than Hb A and exhibits an abnormal functional performance.

We report here a new frameshift mutation in exon 3 of the beta-globin gene, a single nucleotide deletion (-C) in between codons 140/141 (GCC/CTG-->GCC/TG), found in an 8-year-old Argentinean girl with clinical picture of thalassemia intermedia. It leads to a beta-chain that is elongated to 156 amino acids [(141)Trp-Pro-Thr-Ser-Ile-Thr-Lys-Leu-Ala-Phe-Leu-Leu-Ser-Asn-Phe-(156)Tyr-COOH]. The resulting hemoglobin, which we named Hb Florida, was not detected in peripheral blood; however, erythroid hyperplasia and dyserythropoiesis with large inclusion bodies on methyl violet staining were observed in bone marrow, suggesting that this is a hyperunstable variant producing a dominant beta-thalassemia phenotype, since the other beta-allele was completely normal., (2006 Wiley-Liss, Inc.)

We report a case in which the interaction of heterozygosis for both the 0-IVS-II-1 (G->A) mutation and the alpha alpha alpha anti-3,7 allele was the probable cause for the clinical occurrence of thalassemia intermedia. The propositus, a 6-year-old Caucasian Brazilian boy of Portuguese descent, showed a moderately severe chronic anemia in spite of having the -thalassemia trait. Investigation of the alpha-globin gene status revealed heterozygosis for alpha-gene triplication (alpha alpha alpha / alpha alpha). The patient's father, also presenting mild microcytic and hypochromic anemia, had the same alpha and genotypes as his son, while the mother, not related to the father and hematologically normal, was also a carrier of the alpha alpha alpha anti-3,7 allele. The present case emphasizes the need for considering the possibility of alpha-gene triplication in -thalassemia heterozygotes who display an unexpected severe phenotype. The -thalassemia mutation found here is being described for the first time in Brazil.

A patient with Hb H disease resulting from the association of the - alpha 3.7 rightward deletion with the rare (alpha alpha)MM deletion, which removes the entire alpha-major regulatory element (MRE), is reported. This is the first description of an alpha-thalassemic mutation resulting from deletion of the locus-controlling sequences in the South-American population.

Seven unrelated patients with hemoglobin (Hb) H disease and 27 individuals with alpha-chain structural alterations were studied to identify the alpha-globin gene mutations present in the population of Southeast Brazil. The -alpha3.7, --MED and -(alpha)20.5 deletions were investigated by PCR, whereas non-deletional alpha-thalassemia (alphaHphalpha, alphaNcoIalpha, alphaalphaNcoI, alphaIcalpha and alphaTSaudialpha) was screened with restriction enzymes and by nested PCR. Structural alterations were identified by direct DNA sequencing. Of the seven patients with Hb H disease, all of Italian descent, two had the -(alpha)20.5/-alpha3.7 genotype, one had the --MED/-alpha3.7 genotype, one had the --MED/alphaHphalpha genotype and three showed interaction of the -alpha3.7 deletion with an unusual, unidentified form of non-deletional alpha-thalassemia [-alpha3.7/(alphaalpha)T]. Among the 27 patients with structural alterations, 15 (of Italian descent) had Hb Hasharon (alpha47Asp-->His) associated with the -alpha3.7 deletion, 4 (of Italian descent) were heterozygous for Hb J-Rovigo (alpha53Ala-->Asp), 4 (3 Blacks and 1 Caucasian) were heterozygous for Hb Stanleyville-II (alpha78Asn-->Lys) associated with the alpha+-thalassemia, 1 (Black) was heterozygous for Hb G-Pest (alpha74Asp-->Asn), 1 (Caucasian) was heterozygous for Hb Kurosaki (alpha7Lys-->Glu), 1 (Caucasian) was heterozygous for Hb Westmead (alpha122His-->Gln), and 1 (Caucasian) was the carrier of a novel silent variant (Hb Campinas, alpha26Ala-->Val). Most of the mutations found reflected the Mediterranean and African origins of the population. Hbs G-Pest and Kurosaki, very rare, and Hb Westmead, common in southern China, were initially described in individuals of ethnic origin differing from those of the carriers reported in the present study and are the first cases to be reported in the Brazilian population.