Verification of self-report of zygosity determined via DNA testing in a subset of the NAS-NRC twin registry 40 years later.

Journal Article (Journal Article)

The National Academy of Sciences -- National Research Council (NAS-NRC) twin panel, created nearly 50 years ago, had twin zygosity determined primarily via a similarity questionnaire that has been estimated to correctly classify at least 95% of twins. In the course of a study on the genetics of healthy ageing in the NAS-NRC twins, DNA was collected for genome-wide scanning and zygosity confirmation was examined in 343 participating pairs. The sample was supplemented from two other studies using NAS-NRC twins where one or both co-twins were suspected to have Alzheimer disease or another dementia, or Parkinson's disease. Overall 578 twin pairs with DNA were analyzed. Zygosity assignment for 96.8% (519/536) was confirmed via questionnaire. Among 42 pairs whose questionnaire responses were inconclusive for assigning zygosity, 50% were found to be monozygous (MZ) and 50% were dizygous (DZ). There was some evidence for greater misclassification of presumed DZ pairs in the healthy ageing study where participation favored pairs who were similar in having a favorable health history and willingness to volunteer without any element of perceived risk for a specific disease influencing participation.

Full Text

Duke Authors

Cited Authors

  • Reed, T; Plassman, BL; Tanner, CM; Dick, DM; Rinehart, SA; Nichols, WC

Published Date

  • August 2005

Published In

Volume / Issue

  • 8 / 4

Start / End Page

  • 362 - 367

PubMed ID

  • 16176721

Pubmed Central ID

  • 16176721

International Standard Serial Number (ISSN)

  • 1832-4274

Digital Object Identifier (DOI)

  • 10.1375/1832427054936763


  • eng

Conference Location

  • England