rovided, where the <em>names</em> of the named vector
corresponding to the familial relationship and the values of the vector
corresponds to how often that particular familial role appears.</p>
<p>In order to illustrate the different possible families, we will
provide some examples. If no family information is available, but the
age of onset information is still available, we can use the simplest
covariance, which only contains the genetic and full liability of the
index person:</p>
<div class="sourceCode" 