Polimorfismo do gene RHD em indivíduos com fenótipo RhD (RH1) negativo e portadores de aloanticorpo anti-D

• Autor(a) principal: Martin, Fábio de Oliveira [UNIFESP]
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://repositorio.unifesp.br/handle/11600/9941
• topic: Aloimunização; Fenótipo RhD (RH1) negativo; Polimorfismos gene RHD; Polimorfismo genético; Reações antígeno-anticorpo/imunologia; Fenótipo

Background- The D-negative phenotype is the result of the total RHD gene deletion in almost all Caucasians, but it accounts for only about 20% in Africans and 70% in Asians. In Africans the RHDΨ that is an insertion of 37bp in exon 4 is one of the most important causes of the D-negative phenotype. We investigated the RHD polymorphisms in D-negative phenotype mixed Brazilians who developed anti-D alloantibody. Study design and Methods: One hundred and thirty individuals RhD negative associated to anti-D alloantibody were studied for polymorphisms by performing PCR and RHD sequencing . Results: We found that 118/130 (90.76%) of D-negative tested individuals had total RHD gene deletion, while 12/130 (9.24%) showed RHD gene polymorphisms. The RHDΨ was found in 10 (7.70%) individuals who had the insertion of 37pb between the end of intron 3 and exon 4 and the mutations 609 G>A, 654 G >C, 667 T>G, 674C>T, 807 T>G. One sample (0.77%) hybrid RHD-CE-Ds /RHDΨ, and another (0.77%) weak D type 4.2 were characterized due to mutations 186 G>T, 410 C>T, 455 A>C, 1025 T>C / 609 G>A, 654 G >C, 667 T>G, 674C>T, 807 T>G + the insertion of 37pb and 602 C>G, 667 T>G, 957 G>A, 1025 T>C, respectively. Conclusion: The results showed that the RHD gene was present in 9.24% of racially mixed Brazilians who produced clinically significant anti-D alloantibodies. Therefore, the data showed that careful attention is necessary for clinicians in applying RhD genotyping to transfusion medicine in populations with high rate of racial admixture.