Clinical characteristics of PRKACA mutations in Chinese patients with adrenal lesions: a single-centre study

Recent studies have identified that the somatic PRKACA L206R mutation can cause cortisol-producing adenomas (CPAs). This study investigated the prevalence and characteristics of PRKACA, GNAS and CTNNB1 mutations in adrenal lesions in patients from a single centre in China.

We sequenced PRKACA, GNAS and CTNNB1 genes in 108 patients, including 60 patients with CPAs (57 with unilateral and three with bilateral adenomas), 13 with nonfunctional adenomas, 12 with adrenocortical carcinomas (ACCs), 15 with primary bilateral macronodular hyperplasia (PBMAH) and eight with aldosterone and cortisol cosecreting adenomas. Mutations in PRKACA, GNAS and CTNNB1 were examined, and clinical characteristics were compared.

Among the unilateral CPAs, we identified somatic mutations in PRKACA (L206R) in 23 cases (40·4%), GNAS (R201C and R201H) in six cases (10·5%), CTNNB1 (S45C, L46P and S45P) in six cases (10·5%) and CTNNB1 plus GNAS in two cases (3·5%). PRKACA and GNAS mutations were mutually exclusive. Among the patients with nonfunctional adenoma, two carried CTNNB1 mutations. Among the patients with ACC, two carried GNAS and CTNNB1 mutations but none carried PRKACA mutations. One patient showed bilateral CPA, and one PBMAH patient carried PRKACA mutations. No mutations in PRKACA, GNAS or CTNNB1 were identified in the eight patients with aldosterone and cortisol cosecreting adenomas. PRKACA-mutant adenomas were associated with young age, overt Cushing's syndrome and high cortisol levels compared with non-PRKACA-mutant or CTNNB1-mutant lesions.

PRKACA mutations are present in CPAs and bilateral adrenal macronodular hyperplasia. PRKACA mutation is associated with more severe autonomous cortisol secretion.