Documentary filmmaker Morgan Matthews uses his non-fiction BBC telefilm “Beautiful Young Minds” (2007), about the UK team vying for spots at the 2006 International Mathematics Olympiad, as the basis for his first fiction feature, which itself bears a strong comparison to Ron Howard’s Oscar winner “A Beautiful Mind.” Though “A Brilliant Young Mind,” as the film (originally called “X+Y”) has been retitled, lacks the twist that gave Howard’s picture such a dramatic kick, it’s certainly an agreeable if fairly predictable uplifting dramedy, helped by a strong cast.

Matthews and screenwriter James Graham have used the IMO as the background for a narrative about a British boy, Nathan Ellis, who’s diagnosed as autistic and, despite his flair for math, struggles to achieve any sort of socialization after his loving, supportive father Michael (Martin McCann) dies in an auto accident. Initially played by Edward Baker-Close, he remains unable to connect emotionally with his mother Julie (Sally Hawkins) despite her years of effort.

Julie decides that the best thing for her son is to be trained in his math skills and enlists Martin Humphreys (Rafe Spall), a teacher at the local school, to become his mentor. Humphreys is himself a damaged soul, a former IMO prodigy who suffers from MS and feels his physical abilities ebbing away. But he immediately recognizes the boy’s extraordinary promise and begins tutoring him; eventually Nathan grows into a still-skittish teen (Asa Butterfield), and a candidate for the British team at the IMO himself.

The upshot is that Nathan is soon on his way to Taiwan for the preliminary IMO trials, where he finds himself in competition with other brilliant, but often socially troubled kids, not only on the English squad but the Chinese one with whom they’ve been paired. Under the tutelage of Richard (Eddie Marsan), the high-spirited, demanding team trainer, he’s forced to come haltingly out of his shell, especially as a result of a budding relationship with a vivaciously friendly member of the Chinese team, Zhang Mei (Jo Yang).

That relationship continues when the two win spots at the IMO finals back in England; indeed, they grow even closer, until one of their encounters—chaste, but misunderstood—is interrupted. That will force Nathan to make a life-changing choice, just as Julie and Martin—who have also become involved during their years of working together for Nathan’s improvement—are inching toward one of their own.

It must be admitted that in the end the story comes off as rather pat and predictable, but it has sufficient quirks to compensate for its generally formulaic quality. Many are provided by the expert cast: Marsan and Spall in particular bring a good deal of raffish humor, while Hawkins and Jo Yang add tenderness to the mix. But the film wouldn’t work at all without the contributions of Baker-Close and Butterfield, who together make Nathan credible in both his brilliance and his troubled self-absorption. Matthews shows considerable skill in giving the actors ample room to breathe without allowing them to run riot. On the technical level the film is fine, with Danny Cohen’s cinematography making good use of location and perspective.

“A Brilliant Young Mind” hardly breaks new ground, but it’s a watchable entry in the tortured young genius genre.