  We present a stochastic framework to decipher fluctuations propagation in
classes of coherent feed-forward loops. The systematic contribution of the
direct (one-step) and indirect (two-step) pathways is considered to quantify
fluctuations of the output node. We also consider both additive and
multiplicative integration mechanisms of the two parallel pathways (one-step
and two-step). Analytical expression of the output node's coefficient of
variation shows contributions of intrinsic, one-step, two-step, and
cross-interaction in closed form. We observe a diverse range of degeneracy and
non-degeneracy in each of the decomposed fluctuations term and their
contribution to the overall output fluctuations of each coherent feed-forward
loop motif. Analysis of output fluctuations reveals a maximal level of
fluctuations of the coherent feed-forward loop motif of type 1.
