Being world number one in any sport requires a lot of sacrifices, and for Alfie Hewett this week that means missing his GCSE science exams.

Instead, the 15-year-old is part of the Great Britain team in Turkey bidding for success in the World Team Cup, wheelchair tennis' equivalent of the Davis and Fed Cups.

With his team-mate in Britain's junior line-up, 17-year-old Lauren Jones, ranked junior number three, Hewett has high hopes for gold.

'I'm really looking forward to it,' he said. 'It'll be my fourth one. I haven't won a gold medal yet. We got bronze last year but we'll be highly seeded so we should do quite well.'

Hewett, from Cantley near Norwich, is one of the sport's brightest young talents.

This year he has already successfully defended his Junior Masters title, beaten British number two Marc McCarroll twice and won two senior singles titles, winning a total of 31 matches in singles and doubles and losing just two. His men's ranking has climbed rapidly to a high of 26, and his rise is showing no sign of slowing down, with the Rio Paralympics firmly in his sights.

Hewett said: 'I'm really pleased with how it's gone so far this year. Hopefully it can continue. A year ago I wasn't even in the top 100 in the men's rankings. I'm always looking forward and trying to improve.

'My long-term goal is to go to the Paralympics. Rio should be a definite and maybe 2020 as well. I'd like to be top three in the men's rankings but I just want to get the best out of myself.'

So central has tennis been to Hewett's life that he can barely remember how he got into the sport.

Born with a congenital heart defect that required open heart surgery as a baby, Hewett was then diagnosed with Perthes Disease in his left hip at the age of six that left him wheelchair bound.

Recalling his early experiences of tennis, Hewett said: 'My local club had a disability group so I went along to that. It was a bit of fun and it helped take my mind off things.

'I went to some camps at the National Tennis Centre and I played in my first tournament when I was about 10. Ever since then I've just progressed.'

Hewett's school, Acle Academy, has had to get used to the teenager jetting off round the world to play in tournaments, although next year he will miss the World Team Cup so he can sit his science exams.

'Last year I took loads of time off school,' he said. 'They've been great, really supportive. I struggled a little bit at the start of the year but I've been able to catch up.'

Britain will field men's, women's, quad and junior teams in Turkey this week, with all going into the event as medal hopefuls.

The men's team will be led by 21-year-old Gordon Reid, who warmed up for the tournament in perfect fashion by beating world number two Stephane Houdet to win the Internazionali d'Italia in Rome at the weekend.

The Scot said: 'The Team Cup is the only chance we get each year to be part of a team and it's the most similar event to the Paralympics.'

Like Hewett, Reid has enjoyed a superb start to 2013, climbing to sixth in the world rankings and claiming a first win over world number one Shingo Kuneida in South Africa in April.

Next month Reid will play singles at a grand slam for the first time after qualifying for the French Open.

The Helensburgh player said: 'I'm really pleased with my start to the year. I've achieved a couple of my goals already so it's good to tick those off. Beating Shingo was a massive win for me. It was the first time I'd beaten him and the first time he'd lost for quite a few matches.

'I can't wait for the French Open. It'll be my first grand slam in singles. I've beaten all the players that are going to be in the draw so there's no reason I can't win it, although obviously it's going to be very tough.'

Reid's progress has been an inspiration to Hewett, who also lists wheelchair tennis queen Esther Vergeer as a sporting hero.

The Dutchwoman retired in February having won 470 consecutive singles matches in a decade-long unbeaten run.

'She's a big inspiration,' Hewett said. 'I would love to be that person one day. And seeing what Gordon Reid has achieved as well. He still beats me every time but it motivates me.'