Anti-PIT-1 antibody syndrome, firstly reported in 2011, is characterized by acquired GH, PRL, and TSH deficiencies without PIT-1 mutation and is associated with the presence of the circulating antibody against PIT-1 protein as a marker.
Studies on Snell and Jackson mice known to have growth hormone, prolactin and thyroid-stimulating hormone deficiencies involving the hypoplastic pituitary gland have led to identifying alterations of the pituitary specific POU homeodomain Pit-1 transcription factor gene.
The genetic abnormalities include mutations within: (1) Hesx1 (IGHD, SOD or CPHD); (2) Lhx3 (CPHD with preservation of cortisol secretion and a short stiff neck); (3) Lhx4 (GH, TSH and ACTH deficiency with cerebellar hypoplasia); (4) Prop1 (variable CPHD often associated with pituitary masses); (5) POU1F1 (GH, prolactin and TSH deficiency); (6) GHRHR (IGHD) and (7) GH1 (IGHD).
Genetic abnormalities of the pituitary specific transcription factor, Pit-1, have been reported in several patients with GH, prolactin (PRL) and TSH deficiencies.
However, as the involvement of PIT1 mutation is rare in Russia, the other negative cases need to be analyzed for another candidate gene responsible for combined GH/Pr/TSH deficiency.