Biological markers and diagnostic accuracy in the genetics of posttraumatic stress disorder

Family End twin studies suggest a substantial genetic contribution to the e tiology of posttraumatic stress disorder (PTSD). Identification of the natu re of this genetic contribution should enhance understanding of the pathoph ysiology of PTSD and suggest improved therapeutic strategies for its treatm ent. However, a broadly defined phenotype, specific requirement for an envi ronmental exposure and high frequency of comorbid psychiatric illness all c omplicate genetic studies of PTSD, It is likely that genetic heterogeneity, incomplete penetrance, pleiotropy and the involvement of more than one gen e all constitute formidable obstacles to the genetic analysis of PTSD. One way to circumvent these problems is to perform genetic analysis of traits a ssociated with PTSD, rather than PTSD itself, an approach that has been fru itful for other diseases with complex modes of inheritance. Hypothalamic-pi tuitary-adrenal axis hypofunction, physiologic markers of increased arousal , and increased acoustic startle response are all potential PTSD-associated traits that might be susceptible to genetic analysis. However, the capacit y of these traits to distinguish PTSD from non-PTSD patients and their fami lial pattern must be better defined before they can be employed in genetic studies. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.