X2: X-Men United Prologue
When her husband, William Stryker discovers that their son, Jason Stryker, is a mutant, he sends him to Xavier's School for Gifted Youngsters in hopes of ridding Jason of his mutation. Over the next year, Jason grew increasingly angry, resentful, and vindictive towards his parents and blamed them for his condition, to which he began to use his powers to torment them, planting horrific illusions and images in their minds.
Unable to handle the torturous illusions, Marcy eventually committed suicide by applying a power drill to her left temple, and drilling into her own brain in an attempt to "bore the images out". Unable to cope with his wife's death, Stryker vowed to eliminate all of mutantkind.
After his mother's suicide, Jason was given a lobotomy and was cryogenically frozen by his father. When General Munson tried to shut Weapon XI down, he explains how he knows what happened with Styker’s son, and believes that the Colonel is too emotionally close to the situation.
Her husband tells a captured Charles Xavier the whole story of Jason Stryker and his wife and why he hates mutants.
Due to Wolverine traveling back in time to January 1973, and preventing Bolivar Trask from being assassinated by Mystique, and changing the significant events after that point, William Stryker never sent Jason to the X-Mansion, Jason never grew resentful towards his parents, and thus Marcy Stryker never committed suicide.