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HLA‐A polymorphisms in four ethnic groups from Guinea‐Bissau (West Africa) inferred from sequence‐based typing

Publication . Spínola, C.; Bruges-Armas, J.; Brehm, A.; Spínola, H.

Human leukocyte antigen (HLA)-A locus polymorphisms were examined at highresolution level, using sequence-based typing, in the four most representative Guinea-Bissau(NorthwestAfrica)ethnicgroups:Balanta,Bijago´ s,FulaandPapel. DespitetheFulagrouphavingsignificantdifferenceswhencomparedwiththeother three ethnic groups, all four groups most likely received a genetic input from non sub-Saharans. The Bijago´ s and Papel groups showed similarities to neighboring populations from Mali and Senegal. The Balanta, despite their oral tradition of an East Africa origin, show affinities to Cameroon populations, highly influenced by Bantu migrations. These results are congruent with historical sources and other genetic studies that support the finding that the Guinea-Bissau genetic pool was influenced by several migrations from North Africa, Sahara and East Africa.

2008-08Journal article

Restricted access

Discrepancies in HLA Typing by PCR-SSOP and SBT Techniques: a case study

Publication . Spínola, Hélder; Bruges-Armas, Jácome; Brehm, António

Six hundred twenty-one samples from Portugal, the Cabo Verde archipelago, and Guinea-Bissau were typed for HLA-A, HLA-B, and HLADRB1usingthepolymerasechainreaction–sequence-speciﬁcoligonucleotide probe (PCR-SSOP) method and the sequence-based typing (SBT) method to characterizeandcomparediscrepanciesbetweenthetwomethods.Fifty-three alleles (4.27% of 1,242 chromosomes typed) identiﬁed by the PCR-SSOP method were not concordant with the results obtained using the SBT method. Thirty-four (2.74% of total chromosomes typed) PCR-SSOP mistyping results were discrepancies inside the same allele group and 19 others (1.53% of total chromosomes typed) were relative to nonconcordant results between different groups. PCR-SSOP allele mistyping is the result of interpretation difﬁculties resulting from less intense, absent, or dubious hybridization patterns. Noncommercial PCR-SSOP procedures are highly exigent on the technicians’ experience and the availability of properly calibrated high-precision equipment.

2007Journal article

Open access