Short-period lateral superlattices have been fabricated on a vicinal high-mobility GaAs/AlGaAs heterostructure. The superlattices were fabricated by growing one or four (1/2InAs + 1/2GaAs) monolayers in the close vicinity of the two-dimensional electron gas (2DEG). The TEM study approved formation of the lateral superlattice with a period of about 10 nm. Standard Hall-effect measurements revealed anisotropy of the electron mobility in consistence with the direction of the superlattice terraces. A number of unusual features were observed in quantum magnetotransport in the high magnetic field region as compared to the uniform 2DEG, i.e., damping of the amplitude and splitting of the Shubnikov-de Haas peaks. At low negative gate voltage when the new structure became more pronounced and clear we were able to distinguish a periodic structure, which could be interpreted as commensurability oscillations in lateral superlattice with a period of about 8 nm.