Table 3

Power gains associated with dichotomous versus specific radiographic endophenotype descriptors

Study parameters Estimated parameters
SNPDefinition of casesDefinition of controlsN casesN controlsEAFORPower (%)N casesN controlsN total
rs754106Hip OA with superior JSNHip OA with non-superior JSN12655520.540.7218.45241610543470
Hip OA with superior JSNPopulation-based126565000.540.910.0510 66954 82165 490
Hip OAPopulation-based181765000.541.010.00>1 000 000>3 577 325>4 577 325
rs73023563Hip OA with superior JSNHip OA with non-superior JSN12655520.191.6357.7815716862257
Hip OA with superior JSNPopulation-based126565000.201.070.0031 513161 925193 438
Hip OAPopulation-based181765000.190.940.0043 995157 384201 379
rs17050727Hip OA with axial/medial JSNHip OA with non-axial/medial JSN42513920.141.6528.6270523093014
Hip OA with axial/medial JSNPopulation-based42565000.141.434.89116817 86419 032
Hip OAPopulation-based181765000.141.000.00
rs6766414Hip OA with hypertrophic responseHip OA with non-hypertrophic response53112860.241.4212.40113927583897
Hip OA with hypertrophic responsePopulation-based53165000.241.250.92219926 91829 117
Hip OAPopulation-based181765000.241.000.00
rs61837881Hip OA with hypertrophic responseHip OA with non-hypertrophic response53112860.241.397.69129831444442
Hip OA with hypertrophic responsePopulation-based53165000.241.337.15132316 19517 518
Hip OAPopulation-based181765000.241.060.0040 187143 762183 949
rs16869403Hip OA with atrophic responseHip OA with non-atrophic response26715500.102.1158.3633019162246
Hip OA with atrophic responsePopulation-based26765000.101.9342.2538393249707
Hip OAPopulation-based181765000.101.050.00115 540413 324528 864
  • For each variant and stratum we present power (%) based on study-specific effect size, effect allele frequency and case/control ratio from the GWAS on Illumina610k. Similarly we estimated the sample size required to have 80% power to detect the associated signals with genome-wide significance (p=5×10−8).

  • EAF, effect allele frequency; GWAS, genome-wide association studies; JSN, joint space narrowing; OA, osteoarthritis; SNP, single nucleotide polymorphism.