Heritability and Demographic Analyses in the Large Isolated Population of Val Borbera Suggest Advantages in Mapping Complex Traits Genes

Isolated populations are a useful resource for mapping complex traits due to shared stable environment, reduced genetic complexity and extended Linkage Disequilibrium (LD) compared to the general population. Here we describe a large genetic isolate from the North West Apennines, the mountain range that runs through Italy from the North West Alps to the South.The study involved 1,803 people living in 7 villages of the upper Borbera Valley. For this large population cohort, data from genealogy reconstruction, medical questionnaires, blood, anthropometric and bone status QUS parameters were evaluated. Demographic and epidemiological analyses indicated a substantial genetic component contributing to each trait variation as well as overlapping genetic determinants and family clustering for some traits.The data provide evidence for significant heritability of medical relevant traits that will be important in mapping quantitative traits. We suggest that this population isolate is suitable to identify rare variants associated with complex phenotypes that may be difficult to study in larger but more heterogeneous populations

Automatic pedigree reconstruction for genetic studies in isolated populations

This paper describes a tool implemented to automatically reconstruct the pedigree of an isolated population of Northern Italy with the aim of supporting genetic studies. The goal of such studies is to analyze genealogic, clinical and genetic data for genetic dissection of complex diseases. In this context the reconstruction of the population pedigree is fundamental to verify that such population is a genetic isolate and obtain the parental relationships among the individuals participating to the study. The algorithm presented in the paper, from heterogeneous data sources (demographic municipal and parish archives and other data sources), derives the pedigree applying several heuristic rules in a predefined order One of the main difficulties in performing such task stands in the "record linkage" process that requires the definition of a sufficiently general strategy for managing the ambiguities caused by missing or imprecise/erroneous input data. The paper, finally, presents and discusses the preliminary results obtained by reconstructing the pedigree of four villages from the data collected during the first eighteen months of project

Serum Hepcidin Levels Correlate with Phenotypes of the Metabolic Syndrome At Population Level

Hepcidin levels are strongly associated with MS features at population level,independently of subclinical inflammation. This association appears to reflect a response to increasing iron stores in males, while in females some MS traits may directly influence hepcidin levels

Genome Wide Association Analysis of a Founder Population Identified TAF3 as a Gene for MCHC in Humans

The red blood cell related traits are highly heritable but their genetics are poorly defined. Only 5-10% of the total observed variance is explained by the genetic loci found to date, suggesting that additional loci should be searched using approaches alternative to large meta analysis. GWAS (Genome Wide Association Study) for red blood cell traits in a founder population cohort from Northern Italy identified a new locus for mean corpuscular hemoglobin concentration (MCHC) in the TAF3 gene. The association was replicated in two cohorts (rs1887582, P = 4.25E-09). TAF3 encodes a transcription cofactor that participates in core promoter recognition complex, and is involved in zebrafish and mouse erythropoiesis. We show here that TAF3 is required for transcription of the SPTA1 gene, encoding alpha spectrin, one of the proteins that link the plasma membrane to the actin cytoskeleton. Mutations in SPTA1 are responsible for hereditary spherocytosis, a monogenic disorder of MCHC, as well as for the normal MCHC level. Based on our results, we propose that TAF3 is required for normal erythropoiesis in human and that it might have a role in controlling the ratio between hemoglobin (Hb) and cell volume and in the dynamics of RBC maturation in healthy individuals. Finally, TAF3 represents a potential candidate or a modifier gene for disorders of red cell membrane

as a Gene for MCHC in Humans

The red blood cell related traits are highly heritable but their genetics are poorly defined. Only 5-10% of the total observed variance is explained by the genetic loci found to date, suggesting that additional loci should be searched using approaches alternative to large meta analysis. GWAS (Genome Wide Association Study) for red blood cell traits in a founder population cohort from Northern Italy identified a new locus for mean corpuscular hemoglobin concentration (MCHC) in the TAF3 gene. The association was replicated in two cohorts (rs1887582, P\u200a=\u200a4.25E-09). TAF3 encodes a transcription cofactor that participates in core promoter recognition complex, and is involved in zebrafish and mouse erythropoiesis. We show here that TAF3 is required for transcription of the SPTA1 gene, encoding alpha spectrin, one of the proteins that link the plasma membrane to the actin cytoskeleton. Mutations in SPTA1 are responsible for hereditary spherocytosis, a monogenic disorder of MCHC, as well as for the normal MCHC level. Based on our results, we propose that TAF3 is required for normal erythropoiesis in human and that it might have a role in controlling the ratio between hemoglobin (Hb) and cell volume and in the dynamics of RBC maturation in healthy individuals. Finally, TAF3 represents a potential candidate or a modifier gene for disorders of red cell membrane

rs1887582 association in general population cohorts.

<p>rs1887582 association in general population cohorts.</p

rs1887582 replica.

*<p>Illegio-Sauris-Resia.</p