Epidemiology of Gout in French Polynesia
Condition: Gout
MeSH terms: Gout
Study type: Interventional

Summary: 
      Gout is a chronic disease caused by the deposit of monosodium urate (MSU) crystals in body
      tissues secondary to hyperuricemia. Patients with gout suffer severe attacks of acute joint
      pain. As the disease progresses, the joint pain becomes chronic and associated with disabling
      and deformative manifestations called tophi. Gout is strongly associated with various
      comorbidities including cardiovascular disease and chronic kidney failure. Gout is a very
      common disease, affecting 0.9% of the adult population in France and nearly 4% of the
      North-American population. Data from New Zealand show a particularly high prevalence of gout
      among Polynesians (minority populations in New Zealand and other islands of the South
      Pacific) that would be explained by genetic susceptibility and frequently intertwined with
      metabolic diseases. Recent findings obtained from the Polynesian population in New Caledonia
      disclose high prevalence figures close to 7%, a level expected to be confirmed by an
      epidemiology study that will be conducted in parallel with the present study and designed to
      determine the precise prevalence of gout in French Polynesia and the most frequently
      associated genetic variants.
    

Detailed description: 
      International genomic studies conducted in populations with hyperuricemia and gout have
      identified a number of associated alleles. The strength of the association between a given
      allele and gout (or hyperuricemia) provides an indication of the importance of the encoded
      protein in disease pathogenesis. It was in this way that the development of gout was found to
      depend on renal urate transporters that were subsequently targeted by new uricosuric
      therapies.

      Overall, the search for gout-associated genes has mostly been done in the general European
      population and revealed a small number of candidate loci. Most of these only contribute a
      small amount to the heritability for gout susceptibility, suggesting that additional genes
      and mechanisms of genetic influence are yet to be discovered. A common feature of Genome-Wide
      Association studies done so far is that usually large sample sizes are required in order to
      detect differences in allele frequencies and their contribution to different traits between
      test groups. The Polynesian population of French Polynesia possesses characteristics that
      make it particularly attractive to carry out population-based genetic research. Historical
      records indicate that the Polynesians of Tahiti and surrounding islands originate from a
      small founder population that has undergone a number of bottlenecks, eventually becoming a
      genetically homogenous population with a fairly high degree of consanguinity. The combination
      of a historic founder event, continued isolation and recent expansion are all ideal
      properties for a Genome Wide Association Study, as they ensure that 1) population
      stratification will be easy to correct when performing association tests and 2) there are
      likely high-effect variants that were kept at low frequency in mainland Europe due to
      negative selection but rose to high frequencies in the Polynesians via the increase in
      genetic drift or selection through adaptation to a specific environment and diet. Therefore,
      it is plausible that rare variants with large effect on health-related quantitative traits
      may be more easily detectable in Polynesians, even with much smaller sample sizes.
    

Intervention name(s): Epidemiological study
Intervention type(s): Other
Intervention description(s): Questionnaires (quality of life, gout, life habit, comorbidities) anthropometrics and health measures DNA analysis RNA analysis Metabolomic analysis
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: Gout, French Polynesia, Epidemiology