Various topics in the area of genetic epidemiology are to be explored. The first topic is the detection of genetic heterogeneity. Different approaches include: (1). Analysis of segregation distributions within sibships, determining the circumstances under which heterogeneity can be detected; examination of the expected and observed number of families with r affected children (r=1,2,...) is proposed. (2). Incorporating environmental variables into the segregation analysis. The segregation parameter can be made to be a function of maternal and/or offspring varibles. One appropriate function is the logistic. (3). Developing and characterizing a genetic heterogeneity likelihood model for pedigrees. Several forms of a disease are assumed to exist in he population (major locus, polygenic, sporadic). The overall likelihood then weights the posterior likelihood of each pedigree for each mode of inheritance with its prior frequency of occurrence. (4). Characterizing a test for linkage when heterogeneity is present as described by Risch and Baron (in press) and determining its power and robustness. The second topic is demographic effects on genetic analysis. First, a maximum likelihood method for morbidity risk estimation with variable age-of-onset is described, and a method for extension to include effects of reduced fertility and increased mortality is given. Determining the effects of differential fertility and mortality on family size distribution in segregation analysis is proposed. The third topic is development of multivariate methodology for te analysis of major loci with pleiotropic effects. The techniques of latent trait analysis are suggested as a solution to this problem. All methods developed are intended for application where appropriate.

Project Start
1984-06-01
Project End
1987-08-31
Budget Start
1985-09-01
Budget End
1986-08-31
Support Year
4
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Yale University
Department
Type
DUNS #
082359691
City
New Haven
State
CT
Country
United States
Zip Code
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Risch, N (1988) A new statistical test for linkage heterogeneity. Am J Hum Genet 42:353-64
Merikangas, K R; Risch, N J; Merikangas, J R et al. (1988) Migraine and depression: association and familial transmission. J Psychiatr Res 22:119-29
Baron, M; Risch, N (1987) The spectrum concept of schizophrenia: evidence for a genetic-environmental continuum. J Psychiatr Res 21:257-67
Risch, N (1987) Assessing the role of HLA-linked and unlinked determinants of disease. Am J Hum Genet 40:1-14
Risch, N; Reich, E W; Wishnick, M M et al. (1987) Spontaneous mutation and parental age in humans. Am J Hum Genet 41:218-48
Baron, M; Risch, N; Hamburger, R et al. (1987) Genetic linkage between X-chromosome markers and bipolar affective illness. Nature 326:289-92
Risch, N (1986) Conditional linkage analysis of multiple sclerosis data. Genet Epidemiol Suppl 1:387-92
Risch, N; Stein, Z; Kline, J et al. (1986) The relationship between maternal age and chromosome size in autosomal trisomy. Am J Hum Genet 39:68-78
Risch, N; Baron, M; Mendlewicz, J (1986) Assessing the role of X-linked inheritance in bipolar-related major affective disorder. J Psychiatr Res 20:275-88