Ectopic posterior pituitary tissue and paracentric inversion of the short arm of chromosome 1 in twins.

Twin boys with hypopituitarism, hypoplasia of the anterior pituitary gland. ectopic posterior pituitary tissue and paracentric inversion of the short arm of chromosome 1 are described. The smooth appearance at the base of the median eminence and the absence of a pituitary stalk at autopsy in these boys implies that the hypopituitarism resulted from a developmental aberration. It remains to be determined if there is a casual relationship between the chromosome 1 anomaly and hypopituitarism.