Phenotype Standardization is the Urgent Need in Genetic Association Studies of Disc Degeneration - Results of Analysis of Genetic Association of 71 SNPs with Highly Specific Phenotypes in 809 Subjects:

IntroductionAlthough the influence of genetics on etio-pathogenesis of disc degeneration is well recognized, there is a wide variation in the different genes observed to have association with disc degeneration. The clinical and radiographic features of disc degeneration used as phenotypes are quite variable in previously published studies. It is unclear whether the variations in genetic association studies depict variations in ethnicity or selection of phenotypes.MethodsThe purpose of the study was to evaluate the allelic diversity of 71 SNPs related to six different MRI markers of lumbar degenerative disc disease (annular tear, Pfirmann's grading, Schmorl's nodes, Modic changes, Total Endplate Damage score and disc bulge) in a single study population, and analyze how genetic associations can vary in the same study subjects with the choice of phenotype, based on age and sequence of selection of study subjects. Genotyping of cases and controls was performed on Genome wide SNP array to identify potentially ...