3d Geometry

Let the image of the point \(\mathrm{P}(1,2,6)\) in the plane passing through the points \(\mathrm{A}(1,2,0), \mathrm{B}(1,4,1)\) and \(\mathrm{C}(0,5,1)\) be \(\mathrm{Q}(\alpha, \beta, \gamma)\). Then \(\left(\alpha^{2}+\beta^{2}+\gamma^{2}\right)\) is equal to :