In 2014, Judith Newman, a journalist in New York, wrote a charming and poignant column for The New York Times about Gus, her autistic 13-year-old son. The apt headline was “To Siri, With Love”: In Siri, the iPhone’s honey-toned robo-helpmate, Gus discovered much more than an “intelligent personal assistant.” She became Gus’s friend, serving a purpose far beyond the recitation of facts about Gus’s various passions, which include planes, trains, and weather forecasts. As Newman put it, Siri could “actually semi-discuss these subjects tirelessly.”

BOOK REVIEW —  “To Siri With Love: A Mother, Her Autistic Son, and the Kindness of Machines,” by Judith Newman (Harper, 256 pages).

Gus’s parents decided he was just “quirky.” Everyone — therapists, teachers, friends, family members — proved complicit in denying his autism.

The essay was quickly tweeted around the world. It spent a week atop The Times’ “most emailed” list, and inspired 383 comments. The piece led to a book deal, and the result — also titled “To Siri With Love” — is now in bookstores.

Here is the problem with Newman’s book — the only problem, in the opinion of this reviewer: Of the 256 pages, a mere dozen or so are devoted to Siri, or really anything related to Gus’s relationship to computers and the imaginary friends they harbor. Given the title, I kept waiting for a lengthy section on the bond between computers and people with autism.

That never happens, which is just fine with me: Newman pulls a bait and switch in which the switch turns out to be far more compelling than the bait. To give you a sense of how much this book moved me, I’ll just say that never before have I teared up while reading an author’s acknowledgments.

“To Siri With Love” is about far more than Gus and his autism. It is also very much about the rest of his small world as it swirls around him: Gus’s twin, the neurotypical, very typically-teenaged Henry; Gus’s father, John, an octogenarian who is married to Newman but lives elsewhere largely because of his need for routine and order; and Gus’s mother, our trusty narrator and guide to Gus’s world.

Newman begins the story of Gus with the minute he appeared on the planet, well ahead of schedule. Both he and Henry weighed less than four pounds at birth, and both had physical delays, which obscured Gus’s mental differences at first. At 10 months, Gus’s lack of interest in his surroundings was diagnosed as “sensory integration disorder,” yet for the next few years his parents decided he was just “quirky.” Everyone — therapists, teachers, friends, family members — proved complicit in the denial of Gus’s autism.

And so it went until Gus was 6, when a kindly neuropsychologist finally, definitively pronounced him “on the spectrum.” That night, John got into bed with Gus and sobbed.

Newman then gets down to the business of acquainting us with her lovable autistic son, who is obsessed with vehicles but is unlikely ever to be able to drive a car. When he was 8, Gus listened to his iPod only at home, but took the device on every trip to the Apple Store so it could say hello to its friends. For years, he loved women’s feet, in the most guileless of ways, calling them “feeties.” In his innocence, he lets himself get bossed around by the slightly older Parker, who may or may not be his girlfriend.

Then there’s Newman herself, a character as likable as you’re likely to encounter in a memoir not written by Nora Ephron. Her tone is confessional in a way that is not in the least off-putting. She gives us breezy writing at its best: swashbuckling yet warm, honest yet respectful of boundaries — hers, her family’s, the reader’s.

Newman’s observations about parenthood are spot-on, particularly when she describes the often-inadvertent ways in which she manages to embarrass Henry. Gus, on the other hand, is impervious to embarrassment.

The machines Newman refers to in her subtitle include not just Siri, but an entire cast of inanimate objects. Newman sums this up beautifully when describing Gus’s love of trains, and his exactitude with respect to their schedules. One of his favorite places is Grand Central Terminal, where, with permission from conductors, he announces all of the stops on the train’s route. By the time he gets to White Plains and North White Plains, passengers are often applauding.

But one day, a conductor on the New Haven Line gets the order of stops wrong, and when Gus corrects her, she first ignores, then glares at him. Gus begins to cry.

In a tone filled with the indignation that any aggrieved parent would share, Newman writes, “To that cow, I wanted to say: ‘Sure, he was crying because you wouldn’t speak to him. But mostly he was crying because by not announcing the stops and connections correctly, you were dishonoring the train.”

Wisely, Newman waits until the end to bring up the weighty questions of screening a fetus for autism, or whether autism should be “cured.” She acknowledges that these are thorny questions, and concludes that she adores her son just the way he is. He is currently a happy person, she writes, and “autism is so much a part of his Gus-ness.” Judging from what Newman helps us know and appreciate about Gus, it is hard to argue with her conclusion. And whatever one’s thoughts on these matters were at the start of the book, they are likely to be challenged, and altered, by the end.

Katie Hafner is a journalist who writes about health care. She is the author of six works of nonfiction, mostly recently a memoir, “Mother Daughter Me” (Random House), and is at work on a novel. She can be reached on Twitter at @KatieHafner.