Spina bifida in a pre-Columbian Cuban population: A paleoepidemiological study of genetic and dietary risk factors.

A holistic approach is necessary to investigate health in archeological populations. Molecular techniques, particularly multiplex PCR and SNaPshot minisequencing, can be combined with paleopathology and dietary analysis (stable isotope, starch, zooarchaeological analyses) to understand aspects of population health. This article demonstrates how spina bifida, a multi-factorial disease characterized by the midline failure to complete vertebral neural arch formation, can be investigated holistically. Based on skeletal evidence, this disease was prevalent in a pre-Columbian Cuban population from the archeological site of Canimar Abajo (3000-1250 BP). Molecular paleopathological techniques were employed to examine disease potential in this preliminary study, examining 18 individuals (including two individuals with evidence of mild spina bifida, and 16 without such evidence) for four single nucleotide polymorphisms and one insertion sequence associated with spina bifida. The combined effect of these polymorphisms, as well as dietary factors, determines the risk of the population for spina bifida, and these factors united to create the observed high disease prevalence. We demonstrate how molecular paleopathology, corroborated by dietary analyses, can be used within a paleoepidemiological framework to understand population health and disease.

Co-infection of Mycobacterium tuberculosis and Mycobacterium leprae in human archaeological samples: a possible explanation for the historical decline of leprosy.

Both leprosy and tuberculosis were prevalent in Europe during the first millennium but thereafter leprosy declined. It is not known why this occurred, but one suggestion is that cross-immunity protected tuberculosis patients from leprosy. To investigate any relationship between the two diseases, selected archaeological samples, dating from the Roman period to the thirteenth century, were examined for both Mycobacterium leprae and Mycobacterium tuberculosis DNA, using PCR. The work was carried out and verified in geographically separate and independent laboratories. Several specimens with palaeopathological signs of leprosy were found to contain DNA from both pathogens, indicating that these diseases coexisted in the past. We suggest that the immunological changes found in multi-bacillary leprosy, in association with the socio-economic impact on those suffering from the disease, led to increased mortality from tuberculosis and therefore to the historical decline in leprosy.

Detection of a single nucleotide polymorphism in the IL-6 promoter region of ancient nuclear DNA.

In the current study a method was developed to examine the G/C single nucleotide polymorphism (SNP) at position -174 in the IL-6 promoter from nuclear DNA samples isolated from human skeletal remains from Manitoba, Canada, dating to as early as 3500 years ago. The IL-6 (-174) SNP was detected in three ancient samples and determined, as expected, in three out of three to be homozygous G/G. The analysis of cytokine SNPs of ancient nuclear DNA may provide novel insights into the genetic basis of autoimmune diseases and the susceptibility/resistance to infectious agents.