Positional identification of microdeletions with genetic markers.

The positional identification of genetic factors for both simple and complex diseases is difficult. There is increasing evidence that small deletions are a fairly common cause for many genetic diseases and some complex diseases. To date, no statistical basis has been available for the identification of microdeletions in family studies. Here, we present an approach to the identification of novel microdeletions for parent-affected offspring trios. We present several different approaches that can be applied to identify microdeletions and also evaluate the statistical behavior of one of these methods in simulated data. The results show that for the study of single nucleotide polymorphisms, the error rate has an approximately linear effect in decreasing the ability to identify microdeletions. On the other hand, heterogeneity of causation, with only some families showing a microdeletion had a more severe influence upon the ability to identify de novo microdeletions. Copyright 2003 S. Karger AG, Basel