Familial Glucocorticoid Deficiency: A Patient Guide

Familial Glucocorticoid Deficiency (FGD) is a very rare genetic condition that changes how your child’s body handles stress and energy. In a healthy body, the brain and the adrenal glands work together to produce cortisol, a vital hormone that helps maintain blood sugar, manages the immune system, and protects the body during illness. In children with FGD, the adrenal glands are “resistant” to the brain’s signals; even though the brain sends out high levels of a messenger hormone called ACTH to request more cortisol, the adrenal glands are unable to hear the message and cannot produce enough of it ^[1][2].

This specific breakdown usually only affects one part of the adrenal gland. In “classic” FGD, while cortisol is missing, the part of the gland that balances salt and water—producing hormones like aldosterone—typically remains functional ^[3][4]. This makes classic FGD different from many other forms of adrenal insufficiency, as most children with this condition do not face the immediate danger of “salt-wasting.” However, mineralocorticoid status still requires monitoring, as some genetic subtypes can involve salt-wasting over time. Furthermore, isolated cortisol deficiency itself can cause hypoglycemia and life-threatening adrenal crisis if not treated promptly ^[3][5].

Living with FGD is a journey of careful balance and proactive management. By taking a daily medication that replaces the missing cortisol, children can grow, learn, and play just like their peers ^[6]. The most important aspects of care involve maintaining a consistent medication schedule and being prepared for “stressful” times, such as illnesses or injuries, when the body needs extra support to prevent an adrenal crisis. With an early diagnosis, a dedicated medical team, and a clear emergency plan, the outlook for children with FGD is positive, allowing them to lead full and active lives ^[7][6].