We’re apparently deep in John Green territory at the beginning of this teen soap opera based on a YA novel by Nicola Yoon. But while the author of “The Fault in Our Stars” treated the subject of mortality at a young age with a degree of seriousness, in “Everything, Everything” it’s just a crude—and in the end deceptive—device for a cutesy romance. Green’s work might not have been profound, but if this movie is any indication, Yoon’s is simply shallow and sappy.

That isn’t to say that the movie’s young stars don’t make an attractive pair; they’re hardly great actors, but they’re certainly good-looking. Amandla Stenberg is Maddy Whittier, a winsome eighteen-year girl who lives an isolated life with her mother Pauline (Anika Noni Rose), who is also her doctor, in a suburban California home outfitted to maintain a secure environment for her. Maddy suffers from SCID—severe combined immunodeficiency—and to venture outside could be fatal. Her only visitors are her long-time nurse Carla (Ana de la Reguera) and her daughter Rosa (Danube R. Hermosillo).

Maddy aches to be free to experience the world—especially the ocean—but her dream of liberation, symbolized by the figure of a suited astronaut (Sage Brocklebank) who appears periodically in her dreams—is impeded not only by her illness but by the intense watchfulness of Pauline, who, having lost her husband and son in a car crash, is determined not to lose Maddy as well.

All changes when a new family moves in across the street. It’s a troubled bunch with an alcoholic, abusive father, but teen Olly (Nick Robinson) is a charming kid, and flashes his smile at Maddy from the window of his room; she reciprocates, and before you can see shooting stars they’ve gotten close—in a purely platonic sense, of course. Carla will help them actually to get together in the same room—an act that Pauline will treat as a betrayal—but even when Maddy falls ill their puppy love will continue to grow. That will ultimately lead to Maddy’s decision to risk everything to be with Olly, and, after they go off together, brings a revelation that makes a happy ending all too easy.

That weird denouement, unfortunately, is characteristic of the entire picture. “Everything, Everything” presents itself as a portrait of a young woman whose very life is endangered by even a moment’s exposure to the air outside the controlled environment provided by her house, but it treats her condition with ludicrous casualness; Maddy not only ventures outdoors at the drop of a boyfriend, but risks everything by becoming a runaway. Even her devoted nurse supposedly puts her in danger by allowing another person into the girl’s special space (the picture doesn’t even bother to show Olly being “decontaminated” before visiting her).

That nonchalance about the basic premise is accentuated by director Stella Meghie’s overall approach to the material, which is too slick by half, emphasizing woozy teen romanticism over any hint of realism. The gauzy cinematography of Igor Jadue-Lillo and the alternately swooning and tinkling score by Ludwig Goransson add to the soapy ambience. In the end “Everything, Everything” is a disease-of-the-week movie that turns out to be a massive cheat in every possible respect.

It’s possible that some easy-to-please tween girls will find the sight of pretty young Stenberg and Robinson gamboling on the beach, and even sharing a very chaste kiss, enough to make the movie watchable. Since the remainder of the cast frankly contribute little consequential to the mix (though Reguera is likable and Rose is convincingly stern), they are all the picture actually has to offer, and as attractive as they are, that won’t be enough for most people. Ultimately “Everything, Everything” amounts to very little.