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L'objet de ce travail est d'illustrer l'intérêt bio-anthropologique d'une approche pluridisciplinaire des relations entre systèmes génétiques et maladies. A travers l'exemple des associations entre molécules HLA-DRB1 (Human Leucocyte Antigen) et Polyarthrite Rhumatoïde (PR), nous nous proposons de décrire en quoi l'Anthropologie biologique et d'autres disciplines telles l'Immunogénétique, la Génomique structurale et/ou la Rhumatologie s'avèrent complémentaires. Il s'agit de montrer comment, outre son intérêt dans la reconstruction de l'Histoire des populations humaines, l'Anthropologie génétique participe à l'Epidémiologie Génétique. Pour cela, nous exposerons la problématique développée dans le cadre de notre collaboration avec l'Etablissement Français du Sang Alpes-Méditerranée, concernant la variabilité de la distribution des allèles HLA-DRB1 associés à la Polyarthrite Rhumatoïde.

L'étude de la collection ostéoarchéologique du site médiéval de St-Estève-Le-Pont concerne des aspects d'anthropologie funéraire (modalités d'inhumation, analyse spatiale) et d'anthropologie biologique (résultats paléodémographiques, biométriques, paléopathologiques et paléoépidémiologiques). Elle présente l'avantage d'un suivi anthropologique du terrain au laboratoire et se révèle primordiale pour l'étude de ce site, notamment en raison de la rareté de matériel archéologique dans les tombes.Le site de Saint-Estève-Le-Pont, situé dans la commune de Berre-l'Etang (Bouches du Rhône), présente deux ensembles funéraires. Le premier concerne des tombes de typologie diversifiée (sarcophages monolithiques, tombes sous bâtière de tuiles, tombes anthropomorphes sous dallage de pierre, tombes en cercueil, etc...), datées entre leVIème et le XIème siècle et situées autour d'un édifice orienté (probablement une chapelle), ayant subi plusieurs remaniements et destructions. Le second ensemble est situé à environ 50 mètres au nord de l'édifice et se compose de tombes anthropomorphes, sous dallage de pierre orientées E-O et N-S. Il s'agit d'un ensemble plus homogène, sans chevauchement de tombes, correspondant à l'établissement d'un cimetière de type "village" à une époque comprise entre le VIIème et le XIème siècle. L'échantillon paléodémographique de ce site, qui reste en cours de fouille, représente un document exceptionnel pour l'étude des populations provençales du haut Moyen Age encore mal connues.

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Ethnic-historic sources have considered the Comorian population to be the result of an amalgamation of African, Arabian and Southeast Asian groups. AIM: This study seeks to determine the genetic relationships and contributions from Sub-Saharan Africa and Indian Oceania and to reconstruct past migration events. SUBJECTS AND METHODS: The human leukocyte antigen (HLA) polymorphism of a Comorian population was described and analysed. RESULTS: Genetic distances and multidimensional scaling analyses showed complex patterns of genetic differentiation in the Indian Oceanian area as a result of continuous gene flow occurring within the past approximately 2500 years. Nevertheless, the Comorian genetic pool appears to be a mix of Bantu-speaking and Arab populations as testified to by admixture estimations of almost 50-60% and 27-33%, respectively. CONCLUSION: The Comorian population may represent the eastern limit of the recent and massive eastward Bantu expansion. In contrast to the population from Madagascar (Merina), only a restricted influence of Austronesian populations was found.

Because of past recombination event, human leukocyte antigen (HLA) alleles that are not closely related in overall sequence may come to resemble each other in areas coding for peptide binding regions (PBR) of HLA molecules. Peptide binding is likely to be important for the role of HLA molecules in autoimmune disease. As a result, it has been suggested that a strategy of searching for HLA disease associations that groups alleles in functional categories based on PBR motifs may be more successful than conventional strategies based on studying different alleles. Using such functional categorization, we examined the possibility of discriminating subcategories of HLA-DRB1 alleles associated with rheumatoid arthritis (RA) in a Southern French population. HLA-DRB1 genotyping was performed by polymerase chain reaction with sequence-specific oligonucleotide hybridization or sequence-specific primers. HLA-DRB1 alleles were classified according to a functional categorization that defined seven similar subregion structures or restrictive supertype patterns (RSPs) within pocket 4 of HLA-DR peptide binding groove as the molecular basis for grouping these alleles. HLA-DRB1* RSPs "A," "De," "Q," "Dr," "E," " R," and "a" association with susceptibility or resistance to disease was then studied in 200 RA patients versus 200 controls. DRB1* RSP "A" containing the shared epitope alleles (DRB1*0101, *0102, *0401, *0404, *0405, *0408, *1001, *1402; odds ratio [OR] = 4.35; pc < 0.001) had a predisposing effect, with double-dose effect as expected, OR 6.68 (pc < 0.001). Among the six remaining RSPs, two had significantly protective effect: DRB1* RSP "De" (DRB1*0103, *0402, *1102, *1103, *1301, *1302, *1304; OR = 0.33; p(c) < 0.001), and DRB1* RSP "Q" (DRB1*0701; OR = 0.40; pc < 0.001). One had non-significantly protective effect: DRB1* RSP "Dr" (DRB1*08, *1101, *1104, *1106, *12, *1303, *16; OR = 0.68; p < 0.05, pc = not significant [NS]). Three had neutral effect: HLA-DRB1* RSPs "E" (DRB1*0403, *0407, *0901, *1401; OR = 0.71; p = NS), " R" (DRB1*0301, *0302; OR = 0.76; p = NS), and "a" (DRB1*1501, *1502; OR = 0.94; p = NS). The functional categorization allowed us to discriminate among the HLA-DRB1 alleles those that confer a predisposing effect, a neutral effect, and a protective effect in RA.