Heterogeneity Analysis of Breast Cancer Families by Using Age at Onset
as a Covariate
C. Merette, M-C. King, J. Ott
AJHG,50,515--519 (1992)
Abstract
An extension of the usual mixture model of heterogeneity
(two family types, one with and one without linkage) is
proposed by introducing age at onset as a covariate. The
extended model defines age-dependent penetrances where the
exact parametrization of age-at-onset distributions depends
on the given genotype and family type (linked or unlinked).
This extension was applied to breast cancer families. We
postulated that the mean age at onset in individuals affected
by the linked gene was lower than the mean age at onset
in all other affected individuals. Linkage heterogeneity for
breast cancer families was detected at a significance level
of 0.003.
