Genetic Epidemiology, Translational Neurogenomics, Psychiatric Genetics and Statistical Genetics Laboratories investigate the pattern of disease in families, particularly identical and non-identical twins, to assess the relative importance of genes and environment in a variety of important health problems.
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PMID
12626225
TITLE
Zygosity diagnosis in the absence of genotypic data: an approach using latent class analysis.
ABSTRACT
For zygosity diagnosis in the absence of genotypic data, or in the recruitment phase of a twin study where only single twins from same-sex pairs are being screened, or to provide a test for sample duplication leading to the false identification of a dizygotic pair as monozygotic, the appropriate analysis of respondents' answers to questions about zygosity is critical. Using data from a young adult Australian twin cohort (N = 2094 complete pairs and 519 singleton twins from same-sex pairs with complete responses to all zygosity items), we show that application of latent class analysis (LCA), fitting a 2-class model, yields results that show good concordance with traditional methods of zygosity diagnosis, but with certain important advantages. These include the ability, in many cases, to assign zygosity with specified probability on the basis of responses of a single informant (advantageous when one zygosity type is being oversampled); and the ability to quantify the probability of misassignment of zygosity, allowing prioritization of cases for genotyping as well as identification of cases of probable laboratory error. Out of 242 twins (from 121 like-sex pairs) where genotypic data were available for zygosity confirmation, only a single case was identified of incorrect zygosity assignment by the latent class algorithm. Zygosity assignment for that single case was identified by the LCA as uncertain (probability of being a monozygotic twin only 76%), and the co-twin's responses clearly identified the pair as dizygotic (probability of being dizygotic 100%). In the absence of genotypic data, or as a safeguard against sample duplication, application of LCA for zygosity assignment or confirmation is strongly recommended.
DATE PUBLISHED
2003 Feb
HISTORY
PUBSTATUS PUBSTATUSDATE
pubmed 2003/03/11 04:00
medline 2003/05/28 05:00
entrez 2003/03/11 04:00
AUTHORS
NAME COLLECTIVENAME LASTNAME FORENAME INITIALS AFFILIATION AFFILIATIONINFO
Heath AC Heath Andrew C AC Department of Psychiatry, Washington University School of Medicine, St Louis, MO 63108, USA. andrew@matlock.wustl.edu
Nyholt DR Nyholt Dale R DR
Neuman R Neuman Rosalind R
Madden PA Madden Pamela A F PA
Bucholz KK Bucholz Kathleen K KK
Todd RD Todd Richard D RD
Nelson EC Nelson Elliot C EC
Montgomery GW Montgomery Grant W GW
Martin NG Martin Nicholas G NG
INVESTIGATORS
JOURNAL
VOLUME: 6
ISSUE: 1
TITLE: Twin research : the official journal of the International Society for Twin Studies
ISOABBREVIATION: Twin Res
YEAR: 2003
MONTH: Feb
DAY:
MEDLINEDATE:
SEASON:
CITEDMEDIUM: Print
ISSN: 1369-0523
ISSNTYPE: Print
MEDLINE JOURNAL
MEDLINETA: Twin Res
COUNTRY: Australia
ISSNLINKING: 1369-0523
NLMUNIQUEID: 9815819
PUBLICATION TYPE
PUBLICATIONTYPE TEXT
Journal Article
Research Support, U.S. Gov't, P.H.S.
COMMENTS AND CORRECTIONS
GRANTS
GRANTID AGENCY COUNTRY
AA07728 NIAAA NIH HHS United States
AA11998 NIAAA NIH HHS United States
AA13321 NIAAA NIH HHS United States
AA13326 NIAAA NIH HHS United States
DA/CA12854 NIDA NIH HHS United States
GENERAL NOTE
KEYWORDS
MESH HEADINGS
DESCRIPTORNAME QUALIFIERNAME
Adult
Female
Genotype
Humans
Male
Sex Factors
Twins, Dizygotic
Twins, Monozygotic
SUPPLEMENTARY MESH
GENE SYMBOLS
CHEMICALS
OTHER ID's