What is one potential outcome of a mutation in one of the two copies of RAS?

The possible outcome is having cancer sooner than expected, for example, a thyroid cancer.

RAS is a group of proteins that when the gene that codes them gets mutated, the proteins become a cause of cancer.

This can be explained by the two hit theory. In this theory, cancer is the result of the accumulation of mutations that occurs in the DNA of a certain cell.

If one mutation happens, that cell won't become a carcinogenic cell, unless the other copy also mutates. With both copies affected, the cell is carcinogenic and will become way more active, multiplying a lot, which leads to more cells affected.

RAS, a family of related proteins, expresses within all animal cell lineages and organs and involves in transmitting signals inside the whole cell. It converts GTP to GDP by gamma phosphate due to its GTPase activity. It can lead to cancer due to its mutation of proto-oncogenes which causes the cell to be activated.