The Magic Numbers consist of two sibling pairs.

Unlike most sibling pairs, Chuck enjoys his brother, even though he is famous.

All told, four sibling pairs and eight single children have already been or soon will be adopted.

A genome-wide scanning approach in sibling pairs may expedite discovery of novel risk factor genes.

DNA analysis will begin after the 300th concordant sibling pair is enrolled, which we anticipate to be at the end of year 4.

If only concordant sibling pairs are collected, a maximum of only 4 alleles can be identified.

Although the cases and controls are collected more easily than concordant sibling pairs, this approach also has limitations.

Isolated cases are more likely to be available than sibling pairs, increasing the potential for statistical power.

Logistically, the collection of a large number of sibling pairs concordant for stroke is a daunting task.