[Study of an isolated West Indies population. II. Estimation of the inbreeding value (author's transl)]

Saint-Barthélémy, a small island near Guadeloupe, has been isolated since the 18th century. A first estimation of genetic size at each generation gives an estimation of the present inbreeding value due to random genetic drift. It is of the order of half a per cent. A census of matings between closely related persons (first or second cousins), during the three last generation may provide an estimation of the inbreeding value related to choice of mates based on relatedness using Sutter's equation of apparent consanguinity. This estimation is of the same order (0.8%) but is restricted to the cumulative effect of random genetic drift and non-random mating between relatives during these three last generations. A full estimation of remote consanguinity at present time requires a detailed analysis of genealogies.