PIT-1 - CLINICAL ASPECTS

Pit-1 is a transcription factor which is expressed in the somatotrope, lactotrope, and thyrotrope cell population of the anterior pituitary gland from early fetal development throughout life. Mutations in the P it-1 gene result in insufficient expression of this factor, accounting for a form of combined pituitary hormone deficiency for growth hormon e (GH), prolactin, and thyroid-stimulating hormone. Clinical presentat ion at diagnosis can be variable, although all forms finally result in severe growth retardation due to GH deficiency and hypothyroidism. Th e clinical variability is due to other factors than the exact location of the mutation; however, the type of inheritance seems to correlate well with the genotype. Early detection of Pit-1 abnormalities might p revent the sequelae associated with some early and severe presentation s of this disorder.