Swansea University's breakthrough in startle disease cause
Swansea scientists say they have made a breakthrough in identifying a cause of a disease which can lead to newborn baby deaths.
Startle disease leads to an exaggerated reaction to, for example, noise or touch, and can stop someone of any age breathing for minutes.
A study has identified a second gene which can lead to hyperekplexia, which affects one in 20,000 to 30,000 people.
Prof Mark Rees, of Swansea University, said it was a significant finding.
In the past, changes in one particular gene were thought to be the only major cause of this disorder.
But the collaborative new study led by Prof Rees at Swansea alongside other scientists has identified changes in a second gene in 21 cases from around the world.
"What we've done now is taken on a much larger cohort of patients and are able to demonstrate conclusively that this is linked to the disease," said Prof Rees.
"Instead of having six patients that we knew about with mutations, we have increased that to 27."
The study, and another from Madrid, have been published in articles in the Journal of Biological Chemistry.
The effects of the condition can be devastating with symptoms including apnoea [breathing interruption], muscle stiffening and stiff legs.
There are said to be cases where patients are misdiagnosed with epilepsy and therefore not properly treated.
The disease has particularly severe consequences for babies.
"It's worse in babies and it usually gets better as you get older as you have fewer and fewer seizures," said Prof Rees.
"In the first week of life with many of the babies, they will be having dozens, if not hundreds, of those apnoeas every day.
"Every time they're touched, or the nappy is changed, or the lights go on, they will go into a startle and breath holding."
He said it could cause delays in development and learning difficulties.
Although the condition may ease into adulthood, it can still have life-changing direct and indirect effects.
"What we know about adult startlers is they become psychologically or socially withdrawn," said Prof Rees.
"Not everybody, but some because they want to avoid the triggers of the startling.
"Just walking down the street and a horn tooting, playing football and the referee's whistle goes off.
"Imagine someone touching you and you go stiff as a board.
"They can fall and have head injuries."