Familial hyperaldosteronism type I (FH-I) is caused by the unequal recombination between the 11beta-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) genes, resulting in the generation of a CYP11B1/B2 chimeric gene and abnormal adrenal aldosterone production. This evidence concerns the gene CYP11B1 and glucocorticoid-remediable aldosteronism.