Among 22 independent patients from the GENHYPOPIT network who had ACTH deficiency and no identified mutation of TPIT, three of them (13.6%) displayed common variable immunodeficiency (CVID), characterized by defective Ig production.
Genetic mutations of the TBX19 causing isolated CAI are rare but a number of genes encoding transcription factors involved in hypothalamic-pituitary gland development, as well as other genes including POMC and PC1, are associated with ACTH deficiency.