RESUMEN
HLA-F is a non-classical major histocompatibility complex (MHC) gene. It codes class Ib MHC molecules with restricted distribution and less nucleotide variations than MHC class Ia genes. Of the 22 alleles registered on the IMGT database only four alleles encode for proteins that differ in their primary structure. To estimate genotype and allele frequencies, this study targeted on known protein coding regions of the HLA-F gene. Genotyping was performed by Sequence Base Typing (SBT). The sample was composed by 199-unrelated bone marrow donors from the Brazilian Bone Marrow Donor Registry (REDOME), Euro-Brazilians, from Southern Brazil. About 1673 bp were analyzed. The most frequent allele was HLA-F*01:01 (87.19%), followed by HLA-F*01:03 (12.31%), HLA-F*01:02 (0.25%) and HLA-F*01:04 (0.25%). Significant linkage disequilibrium (LD) was verified between HLA-F and HLA classes I and II alleles. This is the first study regarding HLA-F polymorphisms in a Euro-Brazilian population contributing to the Southern Brazilian genetic characterization.
Asunto(s)
Alelos , Bases de Datos de Ácidos Nucleicos , Genotipo , Antígenos de Histocompatibilidad Clase I/genética , Desequilibrio de Ligamiento , Polimorfismo Genético , Brasil , Femenino , Humanos , MasculinoRESUMEN
The new allele presents a point mutation at codon 67.1 (ATCâCTC) resulting in a conservative change from isoleucine to leucine.
Asunto(s)
Alelos , Cadenas HLA-DRB1/genética , Sustitución de Aminoácidos , Secuencia de Bases , Trasplante de Médula Ósea , Brasil , Codón , Dermatoglifia del ADN , Exones , Femenino , Cadenas HLA-DRB1/inmunología , Prueba de Histocompatibilidad , Humanos , Datos de Secuencia Molecular , Polimorfismo de Nucleótido Simple , Alineación de Secuencia , Análisis de Secuencia de ADNRESUMEN
The new allele might have arisen from HLA-A*66:01 through a point mutation at codon 182.1 (ACGâGCG) resulting in a non-conservative change from threonine to alanine.
Asunto(s)
Alelos , Antígenos HLA-A/clasificación , Antígenos HLA-A/genética , Mutación Puntual , Donantes de Tejidos , Secuencia de Bases , Brasil , Humanos , Datos de Secuencia Molecular , Alineación de Secuencia , Análisis de Secuencia de ADNRESUMEN
Bone Marrow Transplant (BMT) is a lifesaving procedure for several diseases. Histocompatibility between host and donor is crucial for the success of this therapy. Since human leukocyte antigen (HLA) genes are the most polymorphic in humans, a foreknowledge of their frequencies and a vast register of volunteer donors are important for patients who need an unrelated donor. This research evaluated data from 3500 HLA-typed donors using PCR-SSP (One Lambda ABDRX kits, low/medium resolution). The allele and haplotype frequencies were calculated from the donor HLA typings. Among the total sample we observed that the allelic groups HLA-A*02, -B*35, and -DRB1*11 had frequencies of 0.228, 0.112, and 0.125, respectively. The haplotype HLA-A*01-B*08-DRB1*03 was the most frequent (0.024). We also compared our results with another study conducted in a Northeastern Brazilian population. The identification of the most common allelic groups and haplotypes is of great interest, not only to know the HLA composition of the population but also to search for the best HLA match for a transplant. However, the search for the perfect match depends on the eventual registration of every specific donor in the national registers for bone marrow donation.