Candidate gene association studies

Valdes AM, Hart DJ, Jones KA, Surdulescu G, Swarbrick P, Doyle DV, Schafer AJ, Spector TD. Candidate gene association study of the prevalence and progression of knee osteoarthritis. Arthritis and Rheumatism 2004 50 2497- 2507. 

Levran O, Londono D, O Hara K, Nielsen DA, Peles E, Rotrosen J, Casadonte P, Linzy S, Randesi M, Ott J, Adelson M, Kreek MJ (2008) Genetic susceptibility to heroin addiction a candidate gene association study. Genes Brain Behav 7 720-729... 

Caveats aside, the five dopamine receptors remain candidates in disease. The pharmacological properties that have been used to group them into dopamine Dj-like and dopamine D -like receptors may also be useful to consider when surveying the dopamine receptor gene association studies. For the most part, the D -like dopamine receptors Dj (50-52) and Dj (53) have not been as widely associated with disease as the D dopamine receptors. The D -like receptors D (54), D3 (55), and D (56) have similar dopamine sensitivities and are much more polymorphic than the Dj-like receptors (49,57). 

TPH mRNA and enzyme activity occurs primarily in the raphe region during the early postnatal period, from day 8 to 22 in rats [23], makes this gene and the genes controlling its activity attractive candidates for association studies. 

Del Zompo, M., Ardau, R., Palmas, M. A. etal. (1999). Lithium response association study with two candidate genes. Mol. Psychiatry, 4(1), S66-S67. 

As the number of SNPs evaluated in an association study increases, a concern arises with false positives. This is true for candidate gene studies, but moreso for whole genome random SNP studies where tens to hundreds of thousands of SNPs will be evaluated. The traditional cutoff for assessing statistical significance (p<0.05] by definition can result in 5% false associations occurring simply by... 

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