[Transcription factors of the anterior pituitary and combined hypopituitarism]

In the recent years, spontaneous and experimental models of hypopituitarism have underlined the involvement of a number of homeodomain transcription factors in different forms of congenital anterior pituitary hormone deficiencies. Indeed, abnormalities of the transcription factor Pit-1 are responsible for combined deficiencies affecting thyrotroph, somatotroph and lactotroph cell lineages both in dwarf mouse strains (Snell, Jackson) and in human patients. More recently, alterations of the Prop-1 gene have been shown to induce a similar phenotype in the Ames mice, and alterations of the human homolog gene have been evidenced in patients with anterior pituitary deficiencies involving the same three lineages together with the gonadotrophs. Gene knock-out experiments have demonstrated the importance of other transcription factors such as Lhx3 and Lhx4 in the development of the normal pituitary gland. These findings illustrate the potential involvement of anomalies of these and many other factors in the various forms of multiple hypopituitarism.