[The pituitary specific transcription factor Pit-1/GHF-1 and PIT1 abnormality].

Pit-1/GHF-1 is a pituitary specific POU-domain DNA binding factor, which transactivates the growth hormone (GH), prolactin (PRL), thyrotropin beta subunit (TSH beta) genes, and PIT1 gene itself. It is indispensable for the differentiation and the proliferation of the cells producing GH, and PRL. Loss of the PIT1 gene function (PIT1 abnormality) results in combined deficiency of GH, PRL, and TSH. PIT1 abnormality serves as a model of transcription factor abnormalities.