Seckel syndrome: A birth defect syndrome with severe short stature and, characteristically, low birth weight, very small head (microcephaly), receding forehead, large eyes, low ears, prominent beaklike protrusion of the nose, and smallish chin. Defects of bones in the arms and legs, dislocations of the elbow and hip, and inability to straighten the knees are all common as is (in boys) failure of the testes to descend into the scrotum (cryptorchidism). Underproduction of all types of blood cells (pancytopenia) occurs in some patients, as does chromosome instability.
Seckel syndrome has been called "bird-headed dwarfism" (a descriptive term that has come to be regarded as pejorative). Inside the small head, unfortunately, there is a very small brain. This usually means developmental delay and, later, mental retardation. About half of Seckel children have IQ below 50. Most children with Seckel syndrome are "friendly and pleasant" but "often hyperkinetic (hyperactive) and easily distracted."
Helmut G.P. Seckel (1900-60) was a pediatrician who fled his native Germany in 1936 for the USA where he became professor and eventually chairman of Pediatrics at the University of Chicago. Dr. Seckel did not discover the syndrome now named for him but he did, in 1960, produce the definitive publication describing the clinical condition based on 2 children he had personally seen with it and 13 reliable + 11 less reliable cases from the medical literature. Alternative names for Seckel syndrome (aside from "bird-headed dwarfism") include: Seckel type dwarfism, nanocephalic dwarfism, and microcephalic primordial dwarfism.