There has been much speculation about a gene or genes which cause lateral and ambling gaits in horses. Recently, a study was done in Sweden and a paper published. The interesting thing is that their research, based on horses and mice, showed that a single gene is responsible.
If find that amazing. Certainly, there was never a doubt in my mind that "gaitedness" is genetic, but I always expected it to be a complex matter, with several genes involved, and maybe enhanced by certain types of conformation.
Anyway, I'm sure that this is just the beginning of more of such interesting discoveries.