Mutations in Pit1 gene were first observed in Snell and Jackson dwarf mice (Li et al., 1990; Flurkey et al., 2001) and cause combined pituitary hormone deficiency (CPHD), and hypoplasia of the anterior pituitary in both mice and humans (Li et al., 1990; Pernasetti et al., 1998; Nakamura et al., 1999; Vallette-Kasic et al., 2001; Cohen and Radovick, 2002; Hashimoto et al., 2003; Kelberman et al., 2009). This evidence concerns the gene POU1F1 and hypopituitarism.