Paleoserology of the Christian population at Sayala (Lower Nubia): an evaluation of the reliability of the results.

A paleoserological study of human remains from the Christian cemeteries of Sayala (Lower Nubia, 6th-11th centuries A.D.) was carried out by applying two techniques (absorption-elution and haemagglutination-inhibition), on two types of substratum (bones and hair), in separate laboratories (Pisa and Prague). The aim of research was to evaluate the degree of repeatability of the results and the reliability of the final paleoserological diagnoses. The results indicated different degrees of repeatability depending on the differential sensitivity of the two techniques and on the nature of the substratum. The frequencies of concordant and discordant final diagnoses within and between the two laboratories and by the two methods were significantly different from those expected under the conditions of random distribution, indicating a consistency in results from different laboratories and methods. The reliability of the resulting gene and phenotype distributions is also supported by their consistency both with the theoretical Hardy-Weinberg equilibrium and with the present distribution of the ABO gene frequencies in Egyptian, Sudanese, and Nubian populations.