The distraught family of a missing five-year-old girl in the UK say the child has mild cerebral palsy and needs regular medication.
April Jones' grandfather Richard Moon and step-grandmother Jean have described how the little girl has a brain condition that "can hinder development and affect posture, balance and movement, but other than experiencing slight problems with her hands, April tries to live a normal life", Britain's Daily Mail has reported.
April's mother, Coral Jones, has made a moving plea for information as British police identified a local man they are questioning.
April was last seen getting into a vehicle on Monday near her home in the rural mid-Wales market town of Machynlleth, triggering a huge search by residents across the area.
Her mother fought back tears as she said: "It's been 36 hours since April was taken from us.
"There must be someone out there who knows where she is and can help the police find her. We are desperate for any news.
"April is only five years old. Please, please, help find her."
The child's disappearance triggered the first nationwide child rescue alert, a high-profile system adopted in 2010.
The Dyfed-Powys Police force named 46-year-old Mark Bridger as the man they have been questioning since Tuesday, in the hope it will bring in more information about his movements.
It appealed for witnesses who may have seen Mr Bridger or his sport utility vehicle between the girl's disappearance and his arrest.
"Please don't assume that someone else has already contacted us. Please, even if you have the smallest of information, it could be crucial to this investigation," said Detective Superintendent Reg Bevan.
"Even if you feel yours is trivial, it may be the vital piece that we are missing."
He said more than 50 volunteers were helping mountain rescue teams in the search.
The police officer said he was confirming Mr Bridger's identity to end speculation, but stressed that the arrested man was just one of several lines of inquiry.
An overnight search failed to find the youngster, and police urged the public - who have turned out in droves to help search for the missing girl - to leave efforts to "members of our trained and skilled teams".