Quark mass dependence of nucleon-nucleon S-wave scattering lengths

In the framework of a Chiral effective theory with dibaryon fields, we calculate the pion mass dependence of the inverse scattering length of the nucleon-nucleon system in the S-3(1) channel at order (m(pi)(3)/Delta(2)(chi)) x (m(pi)(1/2)m(N)(3/2)/8 pi f(pi)(2))(n) for all n >= 0. We show that certain sets of potentially large higher-order contributions vanish. We discuss the difficulties of extending the proof to the S-1(0) channel. We apply our results to chiral extrapolations of current lattice data.