A teenage girl collapsed and died minutes after her first kiss with her boyfriend.

Jemma Benjamin, 18, was kissed by fellow university student Daniel Ross, 21, at his home after a night out together. 

But Miss Benjamin, a long-distance swimmer and hockey player, suddenly slumped on to the sofa and died before Mr Ross's eyes. 

Mr Ross, who had know Miss Benjamin for three months, tried desperately to save her before paramedics arrived on the scene. 

But an inquest into her death yesterday heard that nothing could have been done for Miss Benjamin, who was described as a 'picture of health'. 

The inquest heard that she had died from sudden adult death syndrome (Sads), a rare heart condition which kills 500 in Britain each year. 

Mr Ross told police that he and Miss Benjamin had been friends for three months and in April 2009 they had kissed for the first time at his student flat in Treforest, Pontypridd, South Wales. 

He said: "It was not a sexual relationship but we saw each other a couple of time a week. 

"We were going to go to a bar for some food and went back to my house for a credit card which I had forgotten.  We were talking and ended up kissing in the hallway by the front door. 

"We went into the kitchen and then the living room and Jemma sat down on the sofa." 

Mr Ross said that Miss Benjamin's eyelids 'suddenly began to droop' and her mouth started to froth before she collapsed. 

He said: "I rang her mother to see if she had epilepsy.  She fell in and out of consciousness." 

He dialled 999 and was given resuscitation instructions on the phone by an ambulance service control operator but he was unable to revive her. 

Det Con Richie Andrews, who interviewed Mr Ross, told the inquest in Aberdare: "Jemma and Daniel started chatting and ended up kissing each other - it was possible that it was the first time they had kissed." 

Miss Benjamin's father, Dale, told the hearing that he thought his daughter and Mr Ross were 'just friends.'  He said: "Jemma was very shy and timid." 

A post mortem examination by a pathologist, Dr Jason Shanon, could find no medical reason for Miss Benjamin's death.  She had no history of cardiac problems. 

Miss Benjamin was athletic and sporty but was 'stressed' about forthcoming exams in sports science, the inquest heard. 

Her mother, Charlotte Garwood, said her daughter was a 'picture of health one minute and taken away from me the next." 

She added: "I am not able to put into words how much I miss her." 

Mr Ross has since finished his studies at the University of Glamorgan in Pontypridd and returned to his home city of Birmingham. 

Peter Maddox, the Glamorgan coroner, recorded a narrative verdict. 

After the hearing, Mr Benjamin, 38, a builder of Llantwit Fardre, South Wales, said: 

"We were shocked and devastated that such a fit girl as Jemma should have died."

He said he was setting up an appeal to raise £5,000 for a heart screening programme for young people in the are through the charity CRY - Cardiac Risk in the Young.