Hormonal evaluation showed in all three patients: basal suppressed ACTH, no plasma cortisol suppression after 1-mg over-night dexamethasone suppression test and aberrant adrenal sensitivity in response to several ligands (all data will be shown on poster).
The mother underwent surgical resection of the biliary duct tumor. Histopathology is compatible with a neuroendocrine tumor. Immunostainings and genetic testing are still in progress.
PBMAH is often genetically determined and several genes have been identified, ARMC5 being the last one. Illegitimate receptor expression is observed in the majority of PBMAH. However, the associated-tumors phenotype exhibited by this family does not enter into the spectrum of the described malignancies predisposing syndromes (no hyperparathyroidism). Anyway, investigations are continued in the others children and grandchildren.
This case illustrates the phenotype variability within one family with a rare genetic cause of Cushing's syndrome and highlights the importance of a complete clinical characterization to permit phenotype-genotype correlations for a better knowledge of this disease.