A Kiwi woman finally knows why she's never been able to smile, even when she's thinking the happiest of thoughts.
A team of scientists armed with new DNA technology has pinpointed a rare genetic mutation, providing her with the answer her doctors never could.
Rebecca Clough grew up thinking there was no one else like her. She's never been able to smile. Her facial muscles are paralysed, making eating and drinking difficult. Doctors were mystified.
"Seventeen years we struggled to find out what it was, and then Arthur came along and he had the same condition as Rebecca," says mother Sarah Clough.
But advances in science encouraged a group of Kiwi researchers to take another look at the siblings' genetic code.
"This new technology, which has allowed us to sequence huge amounts of this genetic code all at once and in one procedure on one individual, meant that we are now awash with data," says Dr Stephen Robertson of the University of Otago.
Further detective work lead them to the needle in the haystack - the gene mutation affecting Rebecca and Arthur. Now finally they can name their condition – Carey-Fineman-Ziter syndrome, a muscle disorder so rare only 10 people worldwide have been diagnosed with it, including one American man, still healthy at twice Rebecca's age.
"There's other people with this around the world," says Rebecca. "I was shocked but pretty happy. So I can talk to some of them and see what it's like. It was amazing."
There's no cure but to provide certainty.
"I find it hard to imagine," says Cristin Print of the University of Auckland. "If it was me I'd be incredibly positive and happy that I had that understanding. It doesn't change the condition I have, but it allows me to feel that I'm not necessarily different or wrong, that I actually simply have a change in a gene. I know what the gene is and that's responsible for the change in my body."
"It made a huge difference," says Rebecca. "I can live a normal life, do what normal people do."
It's a one-in-a-billion condition, but at least they now know they are not alone.