The contractor will study multiple mechanisms that have been postualted for Sudden Infant Death Syndrome (SIDS) in the same victims. Seventy-five SIDS victims and a minimum of thirty-five suitable controls sill be identified by the Maryland State Medical Examiner's Office. The Principal Investigator and Co-Principal Invenstigator will receive the appropriately prepared specimens that their portion of the study requires. By evaluating proposed mechanisms in the same SIDS victims, they will determine the relative incidence of the individual abnormalties and their possible interrelationships.