Rosario Ferrigno ^1* Mariacarolina Salerno ² Martin Oswald Savage ³

• ¹ AORN Santobono-Pausilipon, Naples, Italy
• ² Section of Paediatrics, Department of Translational Medical Sciences, University of Naples Federico II, Naples, Campania, Italy
• ³ Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, England, United Kingdom

Defects of the adrenal gland in childhood comprise a broad spectrum of ae ologies, ranging from gene c variants resul ng in adrenal insufficiency 1 , autoimmune dysfunc on 1 , impaired s mula on by the hypothalamic-pituitary axis 1 , and adrenal tumours [2][3][4] , poten ally resul ng in autonomous neoplas c hypersecre on of both adrenal cor cal 3 and medullary steroids 4 . Adrenocor cal hypofunc on can be a life-threatening disorder requiring urgent diagnosis and replacement with glucocor coids 1 . In contrast, hypersecre on of cor sol as in Cushing syndrome leads to specific clinical features such as growth failure, obesity, hirsu sm and osteoporosis, which if undiagnosed can cause major morbidity and decrease in quality of life 3 . Adrenal tumours, including adrenocor cal carcinomas and phaeochromocytomas, may be isolated or a component of familial endocrine neoplas c syndromes, requiring urgent diagnosis, gene c characterisa on, and surgical removal [2][3][4] .In this collec on of ar cles, we describe the rare gene c causes of adrenal insufficiency, discussing the diagnosis, molecular characterisa on, and treatment of adrenal defects, comprising the variegate landscape of familial glucocor coid deficiency syndromes 5,6 . Autoimmune Addison's disease is also discussed and, although rare in childhood, may be isolated or a component of polyendocrine autoimmune dysfunc on in conjunc on with hypoparathyroidism and gonadal insufficiency 7 . The molecular features are also described 7 . The gene c origins of adrenoleukodystrophy are discussed together with the paediatric features, therapeu c approaches and long-term prognos c predic ons 8 .Finally, neoplas c disorders comprising adrenocor cal carcinoma 9 , Cushing syndrome [10][11][12] , and phaeochromocytoma 13 are discussed in detail. Adrenocor cal carcinomas are extremely rare in childhood, but associated with a poor prognosis 9 . Cushing syndrome may be ACTH-dependent, as in Cushing disease, which is the secre on of excess ACTH by a pituitary adenoma or ectopic ACTH syndrome 10,11 , or ACTH-independent as in the case of an adrenocor cal tumour or adrenocor cal hyperplasia, which may be isolated or part of the gene c complex of McCune-Albright syndrome or Carney Complex 11,12 . Guidelines for the management of paediatric phaeochromocytoma are described together with therapeu c recommenda ons for management of hypertension 13 .Our aim in bringing together this collec on of ar cles is to provide clinical and scien fic up-dates to inform and educate both paediatric and adult endocrinologists and their nursing support staff in the broad range of adrenal disorders, which although rare in childhood, can be life-threatening and, by defini serious. The collabora on between paediatric and adult endocrinology staff is emphasised, par cularly in disorders such as familial endocrine neoplasia and Cushing syndrome, where few have wide experience in the management of these disorders.