Abstract: Objective To identify the genetic mutations of aldosterone- and cortisol-coproducing adrenal adenoma in a young boy by whole-exome sequencing. Methods The clinical data of a boy with aldosterone- and cortisol-coproducing adrenal adenoma were collected. Whole-exome sequencing was performed with DNA extracted from the blood and tumor tissue to identify germline and somatic mutations. Results A 13-year-old boy with hypertension and hypokalemia was diagnosed as primary aldosteronism complicated with sub-clinical Cushing's syndrome diagnosed by clinical manifestations and adrenal hormone testing. CT scan found a 4.5 cm×3.6 cm mass in right adrenal gland. The mass was surgically removed and adenoma was proved by pathologic microscopy. A somatic CTNNB1 c.133T＞C (p.S45P) mutation was detected in the adenoma tissue. Somatic mutations, such as KCNJ5, ATP1A1, ATP2B3 and CACNA1D were not detected. Conclusions Somatic CTNNB1 mutation is probably the main cause of this rare disease characterized by aldosterone- and cortisol-coproducing adrenal adenoma. But the profound mechanism needs further study.

Key words: aldosterone- and cortisol-coproducing adrenal adenoma, whole-exome sequencing, liquid chromatograph-mass spectrometer(LC-MS)