Mutations in the GH1 and GHRHR genes shed light on the phenotype and pathogenesis of IGHD whereas mutations in transcription factors such as HESX1, PROP1, POU1F1, LHX3, LHX4, GLI2 and SOX3 contributed to the understanding of CPHD.
In humans, over- and underdosage of SOX3 is associated with X-linked hypopituitarism with variable phenotypes ranging from isolated GH deficiency (GHD) to panhypopituitarism, with or without mental retardation and, in most cases, with reported pituitary imaging, an ectopic/undescended posterior pituitary.
As rare abnormalities, we identified a submicroscopic deletion involving FGFR1 and an SOX3 polyalanine deletion in patients with IHH, and a WDR11 splice site mutation in a patient with CPHD.
Next, we identified a novel seven-alanine expansion within a polyalanine tract in SOX3 in a family with panhypopituitarism in three male siblings with an absent infundibulum, severe APH, and EPP.