A Rare Cause of Adrenal Insufficiency - Isolated ACTH Deficiency Due to TBX19 Mutation: Long-Term Follow-Up of Two Cases and Review of the Literature

Idiopathic Isolated Adrenocorticotropic Hormone Deficiency: A Single-Center Retrospective Study

Idiopathic isolated adrenocorticotrophic hormone deficiency (IIAD) is rare, with high clinical omission and misdiagnosis rates. This study retrospectively collected information on clinical presentation, laboratory findings, and treatment response of 17 patients with IIAD at Jining No. 1 People's Hospital from January 2014 to December 2022. The clinical characteristics were summarized, and the pertinent data were analyzed. As a result, most of the patients with IIAD were male (94.12%), with age at onset ranging from 13 to 80 years. The primary manifestations were anorexia (88.24%), nausea (70.59%), vomiting (47.06%), fatigue (64.71%), and neurological or psychiatric symptoms (88.24%). The median time to diagnosis was 2 months and the longest was 10 years. Laboratory tests mostly showed hyponatremia (88.24%) and hypoglycemia (70.59%). The symptoms and laboratory indicators returned to normal after supplementing patients with glucocorticoids. IIAD has an insidious onset and atypical symptoms; it was often misdiagnosed as gastrointestinal, neurological, or psychiatric disease. The aim of this study was to improve clinicians' understanding of IIAD, patients with unexplained gastrointestinal symptoms, neurological and psychiatric symptoms, hyponatremia, or hypoglycemia should be evaluated for IIAD and ensure early diagnosis and treatment.

A novel TBX19 gene mutation in patients with isolated ACTH deficiency from distinct families with a common geographical origin

Isolated ACTH deficiency (IAD) is a life-threatening condition, particularly in the neonatal period, while a main consequence of undiagnosed isolated ACTH deficiency in survivors is cognitive impairment. TBX19 is involved in the differentiation and proliferation of corticotropic cells and TBX19 mutations are responsible for more than 60% of neonatal cases of IAD. We describe a new variant of the main TBX19 transcript (NM 005149.3, c.840del (p.(Glu280Asp fs*27)), classified as pathogenic, whose pathogenicity is assumed to be due to nonsense mediated decay leading to non-expression of T-box transcription factor TBX19. Moreover we summarize the TBX19 mutations published as individual cases since our last large cohort. Interestingly, this pathogenic variant was identified in four patients from three apparently unrelated families. Two of these families were consanguineous, and after investigations all of three were discovered to have roots in the same mountainous region of northern Morocco, suggesting a founder effect. Early diagnosis, timely treatment (hydrocortisone therapy) and preventive education allowed normal development, growth and quality of life in all patients.