Isolated congenital ACTH deficiency: a cleavage enzyme defect?

Access to files

Full-text and supplementary files are not available from Manchester eScholar. Use our list of Related resources to find this item elsewhere. Alternatively, request a copy from the Library's Document supply service.

Abstract

The pro-opiomelanocortin (POMC) gene encodes adrenocorticotrophin (ACTH) which is derived from precursors by proteolytic cleavage. Congenital, isolated ACTH deficiency is rare but may be familial and fatal. The aetiology is unknown though defects at both hypothalamus and adenohypophysis have been postulated. We have studied a female presenting with hypoglycaemia in the neonatal period. When studied at 6 weeks of age, ACTH was unmeasurable even after injection of corticotrophin releasing hormone (CRH1-41). ACTH precursors, quantitated by two-site immunoradiometric assay, were clearly measurable prior to treatment and were stimulated by CRH1-41 and suppressed by glucocorticoid administration. Concentrations of POMC, N-terminal pro-opiocortin (N-POC) and beta-endorphin (beta-EP) were within the normal adult range during glucocorticoid replacement therapy; ACTH and beta-lipotrophin remained undetectable. The secretion of glucagon, measured by radioimmunoassay, in response to hypoglycaemia was normal. By sequencing polymerase chain reaction products from the patient's genomic DNA, the entire coding region of the POMC gene was established to be normal. The results are compatible with a cleavage enzyme defect.

Keyword(s)

Adrenal Cortex Function Tests; Electrophoresis, Agar Gel; Female; Humans; Infant; Pituitary Function Tests; Polymerase Chain Reaction; analysis: DNA; congenital: Hypoglycemia; deficiency: Adrenocorticotropic Hormone; genetics: Pro-Opiomelanocortin; metabolism: Peptide Hydrolases; physiopathology: Adrenal Cortex; physiopathology: Pituitary Gland, Anterior

Bibliographic metadata

Institutional metadata

Record metadata