Advances in the genetic investigation of SIDS

Abstract

With the recognition through epidemiological studies that the prone sleeping position is a major cause of SIDS, simple measures have led to a significant reduction in its incidence. However, SIDS is still a major cause of infant mortality in the Western world, and in most cases detailed post-mortem examination fails to shed light on a possible aetiology. It is being increasingly recognised that apparent SIDS may be the consequence of a primary underlying genetic disorder, including inborn errors of metabolism (most especially fatty acid oxidation disorders), genetic defects of cardiac conduction (particularly a range of channelopathies), and hyper-trophic cardiomyopathies. In addition, polymorphisms in a number of genes have been implicated in the pathogenesis and incidence of SIDS, although the magnitude of their importance remains to be established. A synopsis of the well-established genetic causes of SIDS will be given in this presentation, along with a brief overview of association studies implicating specific genetic polymorphisms with SIDS. Together, these data raise the question of whether it is timely to consider a ‘molecular post-mortem' for SIDS cases where an underlying aetiology remains unknown.