Rybo-viroxic-nucleic sequences and structures, or RVN, were part of a humanoid's genetic makeup.
RVN was one of the key factors that controlled certain chemical and genetic changes in development during puberty. This was because unlike DNA, which never changed, RVN took on some additional viroxic sequences during adolescence. Those sequences determined how someone developed physically. Without those sequences, people would never mature into adults.
RVN also was a feature of plants like Draebidium calimus.
In 2369, after an unusual transporter accident due to interference from a molecular reversion field, several of the key viroxic sequences of USS Enterprise-D crewmembers Captain Jean-Luc Picard, Keiko O'Brien, Ensign Ro Laren, and Guinan were found to be missing. As a result, they emerged from the transporter as younger versions of themselves though all their memories and mental capacities remained those of adults. The accident also reduced a specimen of Draebidium calimus to seedlings. Accelerating the growth of the plants proved effective in returning them to a mature state, though this would not work on humanoids. Eventually, they were helped by artificial re-insertion of the RVN sequences. (TNG: "Rascals")