BBC--  She had a high threshold for pain, which meant she didn't feel burns or notice broken bones. Five other family members are also affected by the condition which means they are insensitive to pain.

Letizia told the BBC: "From day to day we live a very normal life, perhaps better than the rest of the population, because we very rarely get unwell and we hardly feel any pain.

"However, in truth, we do feel pain, the perception of pain, but this only lasts for a few seconds."

Scientists believe the condition could be down to some nerves not reacting properly.

Researchers who studied the family hope their discovery of a gene mutation in family members could help chronic-pain sufferers in the future.

"We have opened up a whole new route to drug discovery for pain relief," said Prof Anna Maria Aloisi from the University of Siena in Italy.

How is the family affected?

Letizia's mother, two sons, sister and niece all show signs of being affected by the syndrome that is named after the family - Marsili pain syndrome.

She said pain was an important alarm signal and because they feel it only fleetingly, the family often have fractures that go undetected and this leads to inflammation in their bones.

They also experience burns and other injuries without knowing.

Letizia said her 24-year-old son Ludovico, who plays football, has encountered problems.

"He rarely stays on the ground, even when he is knocked down. However, he has fragility at the ankles and he often suffers distortions, which are micro fractures.

"In fact, recently X-rays have shown that he has lots of micro fractures in both ankles."

She said her younger son Bernardo, 21, had a calcification of the elbow without even realising he had broken it after falling off his bike. He continued to cycle for another nine miles.