A Chinese couple are desperately seeking a cure for their daughter who has been laughing non-stop for 12 years.
The Chinese teenager cannot even talk - but has to communicate with different types of giggle.
The mother, Yang Longying, says it started when Xu Pinghui had a fever when she was just eight months old.
Ever since then she has been laughing uncontrollably, the Sun quoted Longying, as saying.
Her dad Xu Weiming added: There is no happiness for us. Seeing her laughing we feel even sadder than if she were crying.
However, the girl has been given new hope after doctors said her brain's frontal lobe might have been damaged by the fever.
They now plan to conduct a CT scan on the teenager and hope this could provide answers to her mysterious condition.