Evidence of a rare gene for low systolic blood pressure in the Framingham Heart Study.

A major risk factor for coronary heart disease in both men and women is elevated systolic blood pressure (SBP). We performed segregation analysis on age, sex-adjusted, and transformed systolic blood pressure data on 1,141 families from the Framingham cohort-offspring study using the segregation analysis program POINTER. The results of hypothesis testing revealed: (1) these data are consistent with familial transmission; (2) there is evidence for the transmission of a rare, major gene for low SBP with a gene frequency of q = 0.02; and (3) most of the transmissible component to SBP can be attributed to the polygenic background with H = 0.31.