Pretty sure this is Teenage Monster (1958).
In a 19th century town in the American Southwest, young Charlie Cannon sees a meteorite crash in the desert. While exploring the crash site, he is exposed to mysterious rays emanating from the meteorite that cause him to begin aging rapidly. His mother, a gold prospector named Ruth, hides him and the town believes him dead. However, in a short time span, he ages ten years, while also becoming a hairy, aggressive, and completely psychopathic man-beast. He sometimes escapes his confinement, and terrorizes the community. After his mother strikes gold, she purchases a house in town in the hopes that living in a real home will soothe her son's inner beast. However, he scares more people and kidnaps a young woman, Kathy. Ruth pays Kathy to keep her silence, but Kathy begins to blackmail Ruth plus manipulate Charlie to kill for her. In the final show-down, Charlie understands Kathy's lies and hurls her off a cliff before being shot and killed himself.
It has the mother and her young son, the meteorite (which irradiates the boy, causing him to mutate), the "seven years later" caption, and then the monstrous face of the grown-up son (who now resembles a wolfman) right afterwards. The son is shown to have killed people, and lives in an old gold mine.
The meteorite scene occurs at about five minutes into the video below.