Japanese family with glucocorticoid-remediable aldosteronism diagnosed by long-polymerase chain reaction

We report a Japanese family with glucocorticoid-remediable aldosteronism (G RA) in whom gene abnormality was identified by the long-polymerase chain re action (PCR) method. The proband was a 21-year-old female incidentally foun d to have high blood pressure (173/107 mmHg). Laboratory tests showed hypok alemia (3.7 mmol/l), and high plasma aldosterone concentration (PAC, 234 pg /ml) with suppressed plasma renin activity (PRA, < 0.1 ng/ml/h). The circad ian rhythm pattern and the results of a rapid adrenocorticotrophic hormone (ACTH) test indicated ACTH-dependent changes in PAC. Imaging studies showed no adrenal mass on either side. A dexamethasone (Dexa) suppression test (1 .0 mg/day orally for 7 days) showed a marked decrease of PAC 2 days after a dministration, and this decreased level was maintained throughout Dexa admi nistration. High blood pressure and hypokalemia also improved during Dexa t reatment. The proband's younger sister was 19 years old and had hypertensio n, PAC of 231 pg/ml, and PRA < 0.1 ng/ml/h. The mother was 53 years old and had hypertension, PAC of 98.5 pg/ml, and PRA < 0.1 ng/ml/h. The proband's elder sister was a 22-year-old normotensive with PAC of 110 pg/ml and PRA o f 0.1 ng/ml. Long-PCR was performed for detection of the chimeric gene asso ciated with GRA, using DNA samples from all four cases and two normal contr ol subjects. Although the aldosterone synthase gene was expressed among all DNA samples, the chimeric gene was detected only in the proband, her young er sister and her mother. Our clinical data and genetic investigation confi rmed the presence of GRA in this Japanese family.