Article
Haplotype analysis and Agamma gene polymorphism associated with the Brazilian type of hereditary persistence of fetal hemoglobin
Registro en:
BORDIN, S. et al. Haplotype analysis and Agamma gene polymorphism associated with the Brazilian type of hereditary persistence of fetal hemoglobin. American Journal of Hematology, v. 58, p. 49–54, 1998.
0361-8609
Autor
Bordin, Silvana
Martins, Juliana T
Gonçalves, Marilda de Souza
Melo, Mônica B
Resumen
Gonçalves, Marilda de Souza “Documento produzido em parceria ou por autor vinculado à Fiocruz, mas não consta à informação no documento”. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Contract grant number: 97/03433/95-0; Contract grant sponsor: Conselho Nacional de Desenvolvimento Científico e Tecnológico; Contract grant number: 300608/95-0. We have identified three unrelated individuals and three members of a family with the
non-deletion form of Ag–hereditary persistence of fetal hemoglobin (HPFH). Molecular
analysis showed that each individual is a heterozygote for a previously described −195 Ag
(C®G) mutation. The b-globin gene cluster was studied using the polymerase chain
reaction and related techniques. Haplotyping using nine restriction sites identified two
closely related chromosomes with the −195 Ag mutation, differing only in a single site 3*
to the b-globin gene. Further analysis of b-globin framework indicated that the HPFH
allele segregates with haplotype V, according to Orkin’s classification. The second haplotype
probably originated by a point mutation or DNA rearrangement of a pre-existing
−195Ag chromosome. We also determined the sequences from −622 to +55 bp upstream
to the Ag gene and part of the Ag IVS-2. We found four polymorphisms associated to the
−195Ag promoter region. All −195 A g chromosomes had a G at positions −588 and +25
relative to the Ag gene. One individual was also homozygous for polymorphisms at −398
(G®A), and another at −369 (C®G). Cloning and sequencing of the polymorphic patterns
of the 3* region of Ag IVS-2 showed that the mutated allele is linked to b-globin chromosome
B. Some correlations between chromosome characteristics and Ag point mutations
were also observed.