Being different is as celebrated as it is alienating.

Teased and ostracised, the young Stephen Wiltshire was bullied by older schoolmates who must have found him an easy target. Diagnosed with autism at three years old, he does not have the ability to interact with the outside world by conventional means.

Life for the 40-year-old today is worlds apart from his childhood. From Jerusalem and Sydney to Rio de Janeiro and New York, the globetrotter travels around the world on invitation to draw city landscapes.

In July, the Brit artist visited Singapore for the first time to sketch an aerial panorama of Singapore’s skyline. The 4m-by-1m artwork was commissioned by Singapore Press Holdings to mark the 30th anniversary of its See The Big Picture project, which aims to highlight the media company’s growth from a print company in 1984 to the multimedia organisation it is now.

The completed piece – drawn entirely from memory after an hour-long helicopter ride over the local skyline – is now displayed at the Urban Redevelopment Authority Singapore City Gallery. It will be presented to President Tony Tan Keng Yam this month as a gift to Singapore for the nation’s 50th birthday next year.

“I like to draw futuristic, modern skyscrapers,” Wiltshire – he uses only German stationery brand Staedtler to draw – tells The Peak his preference of subjects. His favourite Singapore landmark is Marina Bay Sands.

Known for sketching from memory and drawing intricate illustrations of buildings and cityscapes from just a brief site visit, the savant is among the 10 per cent of those with autism who also display extraordinary abilities such as photographic memory, lightning math calculation or musical and artistic talents. Wiltshire, who also plays the piano and has perfect pitch, sings everything from opera to Elvis.

When we met in mid-July, there was little indication of his limited human relational skills. Studies tell us that those with autism may go off the tangent during conversations with the odd non sequitur.

Sure, his older sister Annette, who travels with him, has to rephrase questions so that he knows how to reply. He does not always give eye contact. Still, his confidence shines as he speaks, albeit slowly, and his ear-to-ear grins put one at ease.

At a private dinner, the Londoner also gives a 10-minute long speech. For someone who was all but mute until he was five years old and learned to speak fully only when he was nine, he has certainly come a long way.

Wiltshire, who is of West Indian heritage, spent his first years locked in his private world. Eye contact, even with his mother Geneva, was difficult and his condition worsened after his father died in a motorcycle accident when he was three.

Annette, 42, recalls her embarrassment as a little girl: “Stephen obviously had difficulty dealing with his emotions. He threw tantrums and was screaming a lot. This behaviour had to be explained to my friends and outsiders who didn’t understand because when you look at Stephen, you don’t assume he has autism.

“Back then in the 1970s, it was a condition that was unheard of. There were no books or studies on it. I couldn’t share my feelings with my friends because they didn’t have siblings with autism. It’s just me and Stephen so I did not have other siblings to talk to.”

Her seamstress mother, who is now 68 years old and lives with Wiltshire in London, soldiered on. There’s nothing to be ashamed about, she told Annette.

Annette, who is married but has no children, shares her mother’s viewpoint: “If people don’t understand it, it’s their problem. If you explain it, they will be more open to it. You can’t always please everybody. In the end, it’s about you and the person you want to support.”

While his family fretted about his future, a young Wiltshire already had it sorted out. Annette reveals that at nine years old, Wiltshire already knew he wanted to travel widely to draw. (see side box)

In Wiltshire’s first book Drawings (1987), influential British architect and designer Sir Hugh Casson marvelled at his gift. He wrote in the introduction: “(Wiltshire’s) sense of perspective seems to be faultless… I’ve never seen in all my competition drawing… such a natural and extraordinary talent, that this child seems to have… (he) is possibly the best child artist in Britain.” Wiltshire has three other books on his drawings – Cities (1989), Floating Cities (1991) and American Dream (1993).

Renowned Brit-American neurologist Dr Oliver Sacks noted in his 1995 book An Anthropologist On Mars: “I thought how unlike a Xerox machine (Wiltshire) was. His pictures in no sense resembled copies or photographs, something mechanical and impersonal – there were always additions, subtractions, revisions, and, of course, Stephen’s unmistakable style. They were images and showed us some of the immensely complex neural processes that are needed to make a visual and graphic image. Stephen’s drawings were individual constructions…”

In 2006, he was awarded the Most Excellent Order of the British Empire. His citation does not mention his condition and simply reads: “For services to art”. That same year, the Stephen Wiltshire Gallery opened at London’s prestigious Royal Opera Arcade.

Today, his exhibitions are packed and a long waiting list for commissioned projects stretches up to eight months. Clients pay hundreds of thousands of dollars for his city panorama drawings. He also does human portraits, although these are in his private sketch book.

Indeed, over 150,000 spectators gathered to cheer him on over five days while he worked on the Singapore skyline at Paragon shopping mall’s Main Atrium in July.

Perhaps the artwork is testament to his individuality. In Wiltshire’s interpretation of our skyline, waterfront performance venue Esplanade appears to be hidden from plain sight. He admits that he may not be able to capture everything: “There’s lots of information. Sometimes I forget details and my hand gets tired. But I keep going on.”

Before wrapping up his 10-day visit to Singapore and returning to London, Wiltshire makes a special visit to autism-focused Pathlight School. He interacts with students and listens to their aspirations. He also sketches with 11 students in the auditorium.

A student training as a barista at the in-house cafe wants to brew a cuppa for Wiltshire. But the latter politely declines and says softly: “I’ve brushed my teeth. Maybe later.”

The coffee can wait, while Wiltshire continues to showcase the world’s skylines through his perspective. Next on his wish list are cities such as Montreal, Dallas, Turkey, Houston and Miami which he has never been before.

“There are lots of stories and thoughts,” he says. “I never stop and keep doing the best I can.”