Is it necessary to identify molecular defects in primary immunodeficiency disease?

The identification or the molecular bases of more than 130 primary immunodeficiency diseases has prompted the use of mutation analysis in the diagnostic approach to these patients. Here we discuss the importance of and the limitations associated with molecular diagnosis of these disorders and emphasize the need that mutation analysis be accompanied by appropriate evidence that the identified genetic defect has pathologic consequences on RNA/protein expression and function. U Allergy Clin Immunol 2008;122:1069-73.)