TV REVIEW : LIZA MINNELLI IN MOVIE

In her first TV movie, Liza Minnelli gives a strong, uncharacteristically unmannered performance as the mother of a young muscular dystrophy victim in “A Time to Live,” airing at 9 tonight on Channels 4, 36 and 39.

Even with her bright presence, however, the NBC film is a fairly routine rendering of the “fatal illness drama” that has been a TV-movie staple since “Brian’s Song” in 1971. It predictably elicits our admiration for the family’s battle against the crippling disease and our sympathies for the tragedy that inevitably awaits them, but it does so with formula-dictated situations rather than with fully rounded characters.

Minnelli plays Mary-Lou Weisman, the woman whose 1982 book (“Intensive Care”) was the basis for the movie. She is relentlessly upbeat and self-sacrificing in her efforts to give her son, whom we first meet at the age of 10, as happy a life as possible. We get glimpses of the problems that this obsession causes in her relationships with her husband and other son, but, as with everything else in the film that smacks of ambivalence or complexity, they are quickly glossed over in the unwavering march toward the teary, deathbed finale.