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E K Ginsburg

Publications and source records attributed to E K Ginsburg.

6 recordsLinked to original sources
PubMed1997

Sample size required for predefined linkage decision quality.

A method for estimating the sample size required to attain a predefined linkage decision quality (type I and type II errors) is proposed using the linkage test power estimate developed by Ginsburg et al. [(1996) Genet Epidemiol 13:355-366]. The method is applicable for samples of arbitrarily structured pedigrees collected via proband. Comparison of different ascertainment schemes and pedigree structures by their consequent minimal sample size was performed. For recessive and dominant inheritance with complete penetrance, the relative ranks of the ascertainment schemes are invariant regardless of the true recombination fraction value and the trait and marker gene frequencies, which enables one to point out the better scheme. The feasibility of evaluating a sampling strategy by the cost of pedigree collection is also considered, and comparison between these two methods of sample planning is performed.

Gene Frequency↗
PubMed1996

On planning of samples for linkage analysis: two ways of a sample size reduction.

The sample size required for a given type I and type II errors of linkage decision is determined by using the earlier proposed method of the linkage test power estimation [Ginsburg et al., 1996]. Dependence of the sample size on the heterozygotic genotype penetrance is investigated. Two approaches to sample size reduction are considered: the choice of marker gene and the special extension of analyzed pedigree structures. Their effects are quantitatively evaluated in some illustrative situations. It is shown that a practical reduction in sample size can be achieved only when the added part of a pedigree has a special set of phenotypic characteristics in its members.

Genetic Linkage↗
PubMed1996

On estimation of linkage test power.

Two methods of estimating linkage test power are proposed. The first method is based on the maximum likelihood (ML) estimate of the recombination fraction and is intended for use with a likelihood ratio test (LRT) in the form of a chi 2 or lod score. The power is estimated through a noncentral chi 2 distribution with a specially chosen noncentrality parameter. The second method uses the LRT constructed for a simple alternative hypothesis regarding the recombination fraction value. The approximate distribution of this test and a method of estimating its power is proposed. Using simulated pedigree data, the power estimates for these two methods were shown to be satisfactory. Comparisons among these two methods and the computer simulation approach of Boehnke [1986] are performed.

Genetic Linkage↗
PubMed1994

Demonstration of the X-linkage and order to the genes GLA, G6PD, HPRT, and PGK in two vole species of the genus Microtus.

Using a variety of genetic methods, it is shown in this paper that the genes GLA, G6PD, HPRT, and PGK are X-linked in the vole Microtus subarvalis. The order of these genes has been investigated in two vole species, M. subarvalis and M. kirgisorum, by using the mapping technique of Goss and Harris (1977a, b), which depends on the analysis of gamma-ray-induced gene segregation. The experimental data were processed with the computer programme RHMAP (Ginsburg et al., 1993). The analysis indicated that the correct gene order in M. subarvalis is PGK-HPRT-G6PD-GLA, and the same gene order was found to be the most probable for M. kirgisorum. The relative distances between the genes in the two vole species are apparently the same. The RHMAP programme has also been applied to data previously reported for the same set of X-linked genes in the American mink (Zhdanova et al., 1988), the Australian marsupial Planigale maculata (Dobrovic and Graves, 1986), and man. The evolutionary conservation of the linear order of these X-linked genes in different mammalian taxa is discussed.

Animals↗