Sudden infant death syndrome (SIDS) remains the leading cause of post neonatal deaths, causing over 2000 deaths annually. Despite extensive research, the cause of SIDS is unknown. In the last 15 years, SIDS deaths have decreased following recommendations that infants be placed in the supine position for sleeping. Besides prone sleeping, a variety of other risk factors for SIDS have been identified and increasing attention has been focused on overheating (lethal hyperthermia) as a possible cause for SIDS. Because it is impractical to measure the overnight temperatures of a large number of infants for the entire first year of life (the period of risk for SIDS), other evidence of life threatening hyperthermia will be sought. The HYPOTHESES to be evaluated are that (1) biomarkers for lethal hyperthermia can be identified and that (2) these biomarkers will be present in some SIDS victims. We also hypothesize that (3) a mathematical model of heat production and loss can be used identify SIDS victims that were at risk of lethal hyperthermia.
SPECIFIC AIMS : (1) In an animal model, use DNA microarray technology to identify genes that are differentially expressed in hyperthermia, hypoxia and sudden death to produce a list of candidate genes to be used as biomarkers to identify severe hyperthermia in human studies. (2) In human studies, use DNA microarray technology to confirm the specificity of these biomarker genes in vitro and to seek additional biomarker genes. Test tissue samples from SIDS victims to determine if biomarker genes for hyperthermia are present, indicating a recent episode of severe hyperthermia. (3) Use a mathematical model to analyze data collected at the death scene of SIDS victims and from the bedrooms of healthy infants. This assessment of heat balance will indicate if lethal hyperthermia may have occurred in some SIDS victims and will serve to validate the findings of Aim 2. SIGNIFICANCE: If the hypothesis that some cases of SIDS are caused by hyperthermia is correct, it improves our understanding of SIDS by identifying a mechanism of death and by providing a unifying mechanism for many disparate risk factors for SIDS. If some SIDS victims have died from lethal hyperthermia, public health campaigns specifically directed at diminishing the risk of hyperthermia should substantially reduce the incidence of SIDS. ? ?
| Jardine, David; Cornel, Leanne; Emond, Mary (2011) Gene expression analysis characterizes antemortem stress and has implications for establishing cause of death. Physiol Genomics 43:974-80 |
