Examination of Hardy-Weinberg equilibrium in papers of Kidney International: an underused tool.

BACKGROUND

Population-genetic studies investigating genetic polymorphisms of Mendelian inheritance should always test whether the measured genotype frequencies deviate from the expected one. For this purpose Hardy-Weinberg (HW) criteria are generally used. If genotype distribution of control population misses HW equilibrium, the results should be treated cautiously because the observed genotype distribution in control population does not represent genotype distribution in the overall population. If HW criteria are not fulfilled in the investigated population, this may be further evidence for the correlation between genotype and investigated condition.

METHODS

Between September, 1998, and September, 2003, we tested papers published in Kidney International if HW criteria were ordinarily and correctly checked in studies investigating genetic polymorphisms. Seventy-five genotype distributions of the selected 39 articles were reanalyzed.

RESULTS

HW calculation was reportedly performed in 25 papers (64%). The observed genotype distribution deviated significantly from the expected one in three control, and in 16 patient populations and in three populations of association studies of 15 papers overall; however, this fact was not mentioned in 12 papers.

CONCLUSION

Although the deviation of genotype distribution from the expected one is important information, HW calculations are not performed routinely for each investigated subject groups in these papers investigating genetic polymorphisms.