Wolf-Hirschhorn syndrome was first documented in 1961: a child with midline fusion defects. Subsequent cytogenetic studies revealed a chromosomal deletion of the short arm of chromosome 4. Clinical features include mental retardation, seizures, distinct facial appearance, and midline closure defects. The former Pitt-Rogers-Danks syndromes, caused by overlapping 4p deletions, now are considered as a part of Wolf-Hirschhorn syndrome.