1.   About three thousand inherited abnormalities, ranging from the serious to the mild, have already been identified by scientists and genome research continues to identify more.

2.   This familial vulnerability may result from the inappropriate actions of a depressed parent or from an inherited abnormality in brain chemistry, or both.

3.   These rare cases probably are caused by inherited genetic abnormalities.

4.   Those diseases are often related to inherited genetic abnormalities, but the abnormalities seemingly have no effect for decades.