Archival, demographic and genetic studies define a Sardinian sub-isolate as a suitable model for mapping complex...

Area of Science:

• Population Genetics
• Human Genetics
• Complex Trait Mapping

Background:

• Genetic isolates offer unique advantages for genetic trait mapping.
• However, not all isolates possess the ideal characteristics for such studies.
• The Talana village in Sardinia, a genetic and cultural isolate, was chosen for its suitability.

Purpose of the Study:

• To evaluate the suitability of the Talana population for complex trait mapping.
• To reconstruct the demographic and genealogical history of the village.
• To determine the extent of genetic linkage disequilibrium (LD) and identify ancestral lineages.

Main Methods:

• Reconstruction of village genealogy using historical and archival data.
• Analysis of Y chromosome and mitochondrial DNA for lineage and founder identification.
• Microsatellite analysis in chromosomal region Xq13.3 to assess linkage disequilibrium (LD).

Main Results:

• Reconstructed genealogy confirmed by genetic analyses, indicating fewer founders than initially predicted.
• Approximately 80% of the current population descends from 8 paternal and 11 maternal ancestral lineages.
• Linkage disequilibrium (LD) spans an average of 5 Mb in region Xq13.3.

Conclusions:

• The Talana population is a suitable resource for complex trait mapping due to its isolated nature and defined genetic structure.
• The findings suggest the potential for genome-wide association studies using low-density marker maps to identify regions linked to complex traits.
• Integrating historical, genealogical, and genetic data is crucial for effective population-based genetic studies.