Path Analysis in Genetic Epidemiology

Abstract

The method of path analysis evaluates the importance of genetic and familial environmental effects for explaining the variability in a trait. The method may be applied to data on simple families, twins and other extended families.

Keywords: heritability; familial; twins; correlation

Figure 1.

Hypothetical model of the underlying genetic and environmental factors, and their interactions, giving rise to a complex phenotype. Modeling approximations in terms of a basic model are shown at the bottom. The bottom left diagram depicts the generic model involving an aggregate familial component (T, which includes both genetic and familial environmental effects) and a residual (R). The bottom right diagram depicts a specific model with latent genetic (G), familial environmental (C) and residual (R) sources of phenotypic (P) variation in an individual. Path coefficients are defined in the text. (Reproduced with permission from Rao DC and Rice T (1998) Path analysis in genetics. In: Armitage P and Colten T (eds.) Encyclopedia of Biostatistics, vol. 4. Copyright John Wiley & Sons Ltd.)

Figure 2.

TAU path model of resemblance between relatives in nuclear families (generic model). P denotes a phenotype, T indicates transmissible influences, and the subscripts F, M and C1 and C2 denote father, mother and two children respectively. R denotes the nontransmitted residual environment. Path coefficients are defined in the text. (Reproduced with permission from Rao DC and Rice T (1998) Path analysis in genetics. In: Armitage P and Colten T (eds.) Encyclopedia of Biostatistics, vol. 4. Copyright John Wiley & Sons Ltd.)

Figure 3.

Path model of twin resemblance (under a specific model). P1 and P2 are the observed quantitative phenotypes for two members of a twin pair; G1 and G2 denote latent additive genetic effects which are correlated (1 for monozygotic (MZ) twins and ½ for dizygotic (DZ) twins); C is the latent familial environment shared by both members of a twin pair; R1 and R2 are latent residual environmental influences not shared by the twins. Path coefficients are defined in the text. (Reproduced with permission from Rao DC and Rice T (1998) Path analysis in genetics. In: Armitage P and Colten T (eds.) Encyclopedia of Biostatistics, vol. 4. Copyright John Wiley & Sons Limited.)

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References

Boehnke M and Lange K (1984) Ascertainment and goodness of fit of variance components for pedigree data. In: Rao DC, Elston RC, Kuller LH, et al. (eds.) Genetic Epidemiology of Coronary Heart Disease: Past, Present and Future, pp. 173–192. New York: Alan R Liss.

Cloninger CR (1980) Interpretation of intrinsic and extrinsic structural relations by path analysis: theory and applications to assortative mating. Genetical Research 36: 133–145.

Cloninger CR, Rice J and Reich T (1979) Multifactorial inheritance with cultural transmission and assortative mating. II. A general model of combined polygenic and cultural inheritance. American Journal of Human Genetics 31: 176–198.

Eaves LJ, Fulker DW and Heath AC (1989) The effects of social homogamy and cultural inheritance on the covariances of twins and their parents: a LISREL model. Behavioral Genetics 19: 113–122.

Eaves LJ, Long J and Heath AC (1986) A theory of developmental change in quantitative phenotypes applied to cognitive development. Behavioral Genetics 16: 143–162.

Li CC (1975) Path Analysis: A Primer. Pacific Grove, CA: Boxwood.

Province MA and Rao DC (1985) A new model for the resolution of cultural and biological inheritance in the presence of temporal trends: application to systolic blood pressure. Genetic Epidemiology 2: 363–374.

Province MA, Rice T, Borecki IB, Gu C and Rao DC (2000) A multivariate and multilocus variance components approach using structural relationships to assess quantitative linkage via SEGPATH. Genetic Epidemiology.

Rao DC, Morton NE and Yee S (1974) Analysis of family resemblance. II. A linear model for familial correlation. American Journal of Human Genetics 26: 331–359.

Rice J, Cloninger CR and Reich T (1978) Multifactorial inheritance with cultural transmission and assortative mating. I. Description and basic properties of the unitary models. American Journal of Human Genetics 30: 618–643.

Wright S (1921) Correlation and causation. Journal of Agricultural Research 20: 557–585.

Further Reading

Goldberger AS and Duncan OD (1973) Structural Equation Models in the Social Sciences. New York: Seminar Press.

Hopper JL and Mathews JD (1982) Extensions to multivariate normal models for pedigree analysis. Annals of Human Genetics 46: 373–383.

Kang K and Seneta E (1980) Path analysis: an exposition. In: Krishnaia PR (ed.) Developments in Statistics, vol. 3, pp. 217–246. New York: Academic Press.

Khoury MJ, Beaty TH and Cohen BH (1993) Fundamentals of Genetic Epidemiology. New York: Oxford University Press.

Loehlin JC (1978) Identical twins reared apart and other routes to the same destination. Progress in Clinical and Biological Research 24A: 69–77.

Neale MC and Cardon LR (1992) Methodology for Genetic Studies of Twins and Families. Boston, MA: Kluwer.

Rao DC, Morton NE, Elston RC and Yee S (1977) Causal analysis of academic performance. Behavioral Genetics 7: 147–159.

Rao DC, McGue M, Wette R and Glueck CJ (1984) Path analysis in genetic epidemiology. In: Chakravarti A (ed.) Human Population Genetics: The Pittsburgh Symposium, pp. 35–81. New York: Van Nostrand Reinhold.

Rao DC and Rice T (1998) Path analysis in genetics. In: Armitage P and Colton T (eds.) Encyclopedia of Biostatistics, vol. 4, pp. 3285–3297. Chichester, UK: John Wiley.

Rao DC, Wette R and Ewens WJ (1988) Multifactorial analysis of family data ascertained through truncation: a comparative evaluation of two methods of statistical inference. American Journal of Human Genetics 42: 506–515.

Rice T, Després JP, Daw EW, et al. (1997) Familial resemblance for abdominal visceral fat: the HERITAGE Family Study. International Journal of Obesity 21: 1024–1031.

Van Eerdewegh P (1982) Statistical Selection in Multivariate Systems with Applications in Quantitative Genetics. PhD dissertation, Washington University, St Louis, MO.

Vogler GP, Rao DC, Laskarzewski PM, Glueck CJ and Russell JM (1987) Multivariate analysis of lipoprotein cholesterol fractions. American Journal of Epidemiology 125: 706–719.

Wright S (1978) Evolution and the Genetics of Populations Vol. 4, Variability Within and Among Natural Populations. Chicago, IL: University of Chicago Press.

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Rao, DC, and Rice, Treva(Jan 2006) Path Analysis in Genetic Epidemiology. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0005438]