Published data during a period of almost 40 years revealed 23 studies with 3965 subjects (aged between 38 and 64, with a mean age 56.75 years, and a female-to-male ratio of 1.05) in which a higher PTH in PA versus controls (healthy persons or subjects with essential hypertension) was expected, secondary hyperparathyroidism being associated in almost half of the adults diagnosed with PA. This evidence concerns the gene PTH and essential hypertension.