We selected 65 hypertensive patients and 65 persons to study on the heritability of essential hypertension on Zhoushang isiand. We raeasured the blood pressure of 1006 of their first-degree relatives (parent, sib, child). The results stowed an apparent familial aggregation of high blood pressure. Based on Falconer's formula, the beritability of essential hypertension on Zhoushang island was calculated to be 60%. Here, the heritability as used to reflect the relative influence which the genetic factor and tn...