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Titolo:
A simulation study of the effects of assignment of prior identity-by-descent probabilities to unselected sib pairs, in covariance-structure modeling of a quantitative-trait locus
Autore:
Dolan, CV; Boomsma, DI; Neale, MC;
Indirizzi:
Univ Amsterdam, Fac Psychol, NL-1018 WB Amsterdam, Netherlands Univ Amsterdam Amsterdam Netherlands NL-1018 WB B Amsterdam, Netherlands Vrije Univ Amsterdam, Dept Psychol, Amsterdam, Netherlands Vrije Univ Amsterdam Amsterdam Netherlands chol, Amsterdam, Netherlands Virginia Commonwealth Univ, Virginia Inst Psychiat & Behav Genet, Richmond, Virginia Commonwealth Univ Richmond VA USA hiat & Behav Genet, Richmond,
Titolo Testata:
AMERICAN JOURNAL OF HUMAN GENETICS
fascicolo: 1, volume: 64, anno: 1999,
pagine: 268 - 280
SICI:
0002-9297(199901)64:1<268:ASSOTE>2.0.ZU;2-K
Fonte:
ISI
Lingua:
ENG
Soggetto:
LINKAGE ANALYSIS; POWER; BEHAVIOR; TWIN;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
26
Recensione:
Indirizzi per estratti:
Indirizzo: Dolan, CV Univdsmsterdam, Fac Psychol, Roetersstr 15, NL-1018 WB Amsterdam, Netherlan Univ Amsterdam Roetersstr 15 Amsterdam Netherlands NL-1018 WB n
Citazione:
C.V. Dolan et al., "A simulation study of the effects of assignment of prior identity-by-descent probabilities to unselected sib pairs, in covariance-structure modeling of a quantitative-trait locus", AM J HU GEN, 64(1), 1999, pp. 268-280

Abstract

Sib pair-selection strategies, designed to identify the most informative sib pairs in order to detect a quantitative-trait locus (QTL), give rise to a missing-data problem in genetic covariance-structure modeling of QTL effects. After selection, phenotypic data are available for all sibs, but marker data-and, consequently, the identity-by-descent (IBD) probabilities-are available only in selected sib pairs. One possible solution to this missing-data problem is to assign prior IBD probabilities (i,e., expected values) to the unselected sib pairs. The effect of this assignment in genetic covariance-structure modeling is investigated in the present paper. Two maximum-likelihood approaches to estimation are considered, the pi-hat approach and the LED-mixture approach. In the simulations, sample size, selection criteria, QTL-increaser allele frequency, and gene action are manipulated. The results indicate that the assignment of prior IBD probabilities results in serious estimation bias in the pi-hat approach. Bias is also present in the LED-mixture approach, although here the bias is generally much smaller. The null distribution of the log-likelihood ratio (i.e., in absence of any QTL effect) does not follow the expected null distribution in the pi-hat approach after selection. In the LED-mixture approach, the null distribution doesagree with expectation.

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Documento generato il 22/01/20 alle ore 09:20:19