Familial

[Dr. R.W. Keen]

When dealing with a quantitative trait (QT) (i.e blood pressure) it is usual to 
define disease at one extreme of the normal distribution. If selecting probands/
sibs at this extreme is it possible to work out a familial risk ratio for this
"disease" state or is this wrong? Does anyone out there know if you can 
calculate familial risk (using Risch's model) for a QT or is there another way.

Thanks

Dr Richard Keen