In the mid-1800s English doctor John Langdon Down was appointed director of a home outside London for mentally handicapped children, where he studied their symptoms. In 1862 he described the case of one of his wards who was short and had stubby fingers and unusual eyelids. The boy's condition was later labeled with his surname. But the genetic cause of Down syndrome was not uncovered for another century. In 1959 French pediatrician Jrome Lejeune discovered that these children have three copies of chromosome 21, instead of the standard two.