Cholinergic Receptor, Nicotinic, Beta 4 (CHRNb4)

The nAChRs are thought to be (hetero)pentamers composed of homologous subunits.Lou et al.  reported a generalized MDR (GMDR) method that permitted adjustment for discrete and quantitative covariates and was applicable to both dichotomous and continuous phenotypes in population-based studies of various designs. They applied the method to a genetic study of 4 genes that were reported to be associated with nicotine dependence : CHRNA2, CHRNB4, BDNF, and NTRK2. They found significant joint action between CHRNB4 and NTRK2. Lou et al.  commented that ubiquity of joint actions appears to be a natural property of complex inherited traits and that the term """epistasis,""" coined for a specific type of gene-by-gene interaction, has evolved to have different meanings in biologic and statistical genetics.