title: Estimation of modified concordance ratio in sib-pairs: effect of consanguinity on the risk of congenital heart diseases.
abstract: Family studies are widely used for research into genetic and environmental influences on human traits. In this paper, we establish statistical methodology for the estimation of a new measure of sib similarity with respect to dichotomous traits measured on each member of within family sib-pair. We call this parameter "excess risk." For inference problems involving a single sample, we construct a large sample confidence interval on the concerned parameter. It has long been suspected that consanguinity is a risk factor for many genetic defects. Therefore, we establish a procedure to test the significance of the difference between excess risk parameters in a sample of consanguineous marriages and another sample of non-consanguineous marriages. We apply the methodology to data from a hospital-based congenital heart defects registry in Saudi Arabia, a population in which consanguinity is quite common.
authors.affiliation: King Faisal Specialist Hospital and Research Centre, Saudi Arabia.
authors.forename: Mohamed M
authors.initials: MM
authors.lastname: Shoukri
authors.forename: Allan
authors.initials: A
authors.lastname: Donner
authors.forename: Nadia Abdalla
authors.initials: NA
authors.lastname: Dessouky
authors.forename: Shazia
authors.initials: S
authors.lastname: Subhani
authors.forename: Mansour
authors.initials: M
authors.lastname: Al-Joufan
authors.forename: Ahmed
authors.initials: A
authors.lastname: Al-Omrani
authors.forename: Futwan
authors.initials: F
authors.lastname: Al-Mohanna
authors.forename: Zohair Y
authors.initials: ZY
authors.lastname: Al Halees
mesh_terms: D016022:Case-Control Studies; D016001:Confidence Intervals; D003241:Consanguinity; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics; D006801:Humans; D015994:Incidence; D016013:Likelihood Functions; D008297:Male; D009010:Monte Carlo Method; D012016:Reference Values; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D012529:Saudi Arabia / Q000453:epidemiology; D035781:Siblings