Measures of Autozygosity in Decline: Globalization, Urbanization, and Its Implications for Medical Genetics
2009

Decline of Autozygosity in North American Populations

Sample size: 809 publication 10 minutes Evidence: high

Author Information

Author(s): Michael A. Nalls, Javier Simon-Sanchez, J. Raphael Gibbs, Coro Paisan-Ruiz, Jose Tomas Bras, Toshiko Tanaka, Mar Matarin, Sonja Scholz, Charles Weitz, Tamara B. Harris, Luigi Ferrucci, John Hardy, Andrew B. Singleton

Primary Institution: National Institute on Aging

Hypothesis

How have demographic trends in the past century influenced levels of autozygosity in North American populations?

Conclusion

The study found that autozygosity has declined in North American populations due to increased mobility and urbanization.

Supporting Evidence

  • Older participants showed more homozygous runs than younger participants.
  • The study replicated findings in a subgroup of 477 participants from the Baltimore Longitudinal Study of Aging.
  • Statistical models predicted a 14.0% decrease in the frequency of runs of homozygosity over the 20th century.
  • Increased mobility and urbanization are linked to decreased autozygosity.
  • The trend of decreasing autozygosity may reduce the burden of rare recessive diseases.

Takeaway

As people move around more and live in cities, they are less likely to marry their relatives, which means fewer genetic similarities.

Methodology

The study analyzed runs of homozygosity in two cohorts of North Americans to assess trends in autozygosity.

Potential Biases

Potential bias due to the selection of participants from specific cohorts.

Limitations

The study primarily focused on North Americans of European descent, which may limit the generalizability of the findings.

Participant Demographics

809 unrelated North Americans of European descent, aged 19–99 years.

Statistical Information

P-Value

p<0.01

Confidence Interval

95% confidence interval for estimates of autozygosity decline.

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pgen.1000415

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