Familial glucocorticoid deficiency (FGD) is a rare autosomal recessive disorder, 
in 40% of patients caused by mutation in the ACTH receptor gene. In the 
remaining affected persons most probably mutation refers to regulatory region of 
ACTH receptor or other factors responsible for differentiation of the adrenal 
cortex. FGD is characterized by elevated ACTH and low serum morning cortisol 
level that does not respond to exogenous ACTH stimulation. Mineralocorticoid 
function remains unaffected. Clinical symptoms of FGD are due to glucocorticoid 
deficiency and are manifested in infancy or early childhood. Typically they 
include skin hyperpigmentation, failure to thrive, hypoglycaemia, which in some 
children may be lethal. Allgrove's syndrome, is considered to be a separate 
condition, characterized by glucocorticoid deficiency along with alacrimia, 
achalasia and neurological deficits. Treatment of FGD includes substitution of 
glucocorticoids with dose adjustment depending on the clinical state. Such 
treatment usually prevents from hypoglycaemia and provides normal growth and 
development of the patient.