At 27, designer Christopher Kane is the wunderkind of British fashion. And now, with a line for Topshop, his high-glamour style is about to hit the high street. Carola Long meets him

It's all about brainwashing," jokes Christopher Kane when we meet at his East London studio. He's talking about his new range for Topshop Boutique. "Catch them young and infiltrate their minds. I love the fact that I will reach a bigger audience," he says.

If the Scottish-born designer sounds a little like a cult leader, albeit a melodic-voiced, tongue-in-cheek one, it would match the cult following he has attracted since he graduated from Central Saint Martins College in 2006. Now, however, his designs are set to seduce a new swathe of shoppers when his 39-piece collection – the largest Topshop Boutique designer collaboration yet – arrives in stores on Friday, just in time for the fashion pack to snap up the collection and wear it to London Fashion Week. Kane's show – amongst the hottest tickets of the week – takes place on the following Monday.

With its emphasis on body-con and babydoll shapes, many rendered in a fine black gauze, the Topshop Boutique range feels like quintessential Christopher Kane. There are strong echoes of his previous collections in the clothes, shoes and bags. The mini eyelets and mirrors which embellish sheer leggings, figure-hugging body stocking dresses, a denim jacket and even a grey jersey hooded top, recall the brass metal rings of his graduate collection. The pink and yellow neon shades, which Kane, 27, describes as "essential really", recall the fluorescent hues of his spring/summer 2007 show. A stop-and-stare T-shirt featuring a hungry-looking crocodile with a gaping jaw, "branched out from the killer monkey, Planet of the Apes ideas from spring/summer 2009", says Kane. "All those crazy monkeys are actually quite beautiful."

What's with the angry animal images, which also appear on his line of T-shirts in the form of chimps, baboons and mandrills? "You know, I think my obsession with dangerous animals comes from being really terrified of things," he muses. "Sharks, snakes, crocodiles; even monkeys freak me out. I'm terrified of snakes so I did a snakeskin-print collection ... ha ha!" It transpires that Kane is a big fan of YouTube and in particular reruns of a programme called Untamed and Uncut. "It's about things that go wrong with animals and it's shaw-king," he says with dramatic Glaswegian emphasis, much wild hand gesturing and the hint of relish that reveals a black sense of humour. "You'll die. People dive with sharks and the shark goes crazy, a crocodile wrestles this man's arm off." He pauses. "I like the fact that the crocodile on my T-shirt has really clean teeth," he says.

This observation is a quirky manifestation of Kane's famous attention to detail. When he met Anna Wintour straight after his graduate show, one of the things she said was that his work was too complex to be easily copied. The high street has been awash with Kane-esque designs ever since he caught the attention of the fashion industry, but as predicted they are generally pale imitations of his craftsmanship. His current autumn/winter collection features graphic black and white dresses with Art Deco shapes made from appliquéd strips of velvet, and an interplay of sheer and opaque textures. Kane says he was keen to give the Boutique collection "an element of detail that would make it feel non-high street", and he has.

Kane's Central Saint Martins MA collection, in 2006, was remarkable not only for his fresh colours and body conscious shapes but also his irreverently intricate detail in the form of dresses made from lace or mesh-panelled dresses, metal rivets and lace ruffles. Wintour said that the designs reminded her of Gianni Versace and suggested that Kane met Donatella. "Next thing you know I'm backstage at the show," recalls the amiable designer, where Donatella duly offered him a job. However, Fashion East founder Lulu Kennedy advised him to apply for the Topshop New Generation (Newgen) programme, whereupon Kane decided to "do my own thing". But, having turned down a full-time job with Versace, he still works for them through consulting or his capsule range of accessories for the newly-revived Versus line. Kane had the maximum four seasons supported by Newgen, and is now sponsored by Topshop. The Newgen scheme was established in 1993 by the British Fashion Council to promote new designers; "alumni" include Alexander McQueen, Matthew Williamson and Giles Deacon. Sponsored by Topshop since 2001, designers receive between £5,000 and £10,000. Not only does the scheme help designers set up their own labels, it provides a link between catwalk, high street and consumers, as designers usually create a capsule collection for Topshop in return. Kane's range will be sold in as many stores as Kate Moss's.

Much of Kane's success is thanks to his working partnership with his older sister Tammy, with whom he has been incredibly close since they used to watch The Clothes Show together as kids. He even saved his pocket money to pay for a pink, rubber-look dress for her school leavers' ball – by Versace, appropriately enough. "We have always worked with each other, so it was only natural to progress that," he says. Tammy looked after their father's engineering company after he died in 2002. "She's got a really good business head and a strong instinct, and as a woman she can relate directly to our audience."

Not that Kane seems to have much trouble relating to his customers. While his early collections were probably more suited to Carine Roitfeld-shaped women (the French Vogue editor is an inspiration), his last show had an elegance and sophistication that would flatter practically anyone. His Topshop range is perfectly pitched for shoppers who want something daring and sexy, but intelligently so. Kane also has an unexpected insight into Topshop's products. Like numerous men in search of a seriously skinny fit, he's teamed a black Prada cardigan and COS T-shirt with their women's Baxter jeans, in a snake-hipped 28in waist. "Men's jeans have no stretch," he complains.

Christopher Kane's rapid success reads like a fashion fairy tale, even down to Donatella Versace and Anna Wintour as unlikely fairy godmothers. But, while his life might sound charmed, the past few years have involved a lot of hard work. "I went from student to panic stations overnight," he says, with a stressed expression. "I wish I had a diary of that process because it was so fast." How does he feel now? "I was really worried about the whole recession, but we have actually opened up more stockists, and just as we were about to freak out, we sold out on Net-a-Porter." He says life as a designer can be less glamorous than people might think; he often can't be bothered to go to fashion parties, preferring to hang out near his East London home. When his mum comes to London, "thinking it's going to be party, party", he's actually, "exhausted and completely drained of all energy. When it comes to fashion. I sleep it, eat it, breathe it." Being a darling of the British catwalk – and now the British high street – is a full-time job.