  Small discrete family symmetries such as S4, A4 or A5 may lead to simple
leading-order predictions for the neutrino mixing matrix such as the bimaximal,
tribimaximal or golden ratio mixing patterns, which may be brought into
agreement with experimental data with the help of corrections from the
charged-lepton sector. Such scenarios generally lead to relations among the
parameters of the physical leptonic mixing matrix known as solar lepton mixing
sum rules. In this article, we present a simple derivation of such solar sum
rules, valid for arbitrary neutrino and charged lepton mixing angles and
phases, assuming only {\theta}13^{\nu} = {\theta}13^e = 0. We discuss four
leading-order neutrino mixing matrices with {\theta}13^{\nu} = 0 which are well
motivated from family symmetry considerations. We then perform a
phenomenological analysis of the scope to test the resulting four solar sum
rules, highlighting the complementarity between next-generation neutrino
oscillation experiments such as the reactor experiment JUNO and a superbeam
experiment.
