Low myocardial transcript variant alt-a of cyclin dependent kinase inhibitor p21 expression differentiates hypothermia from cardiac/respiratory causes of death

Gene expressions in the myocardium have been shown to vary between different causes of death, which can be utilized in the recognition of varied processes. Our previous work with a limited number of cases showed a high messenger ribonucleic acid expression of the transcript variant alt-a of cyclin dependent kinase inhibitor p21 (p21 alt-a) in chronic cardiac ischemia deaths and a low expression in hypothermia deaths and acute myocardial ischemia deaths. In present work, p21 alt-a expression in the myocardium of human cadavers was calculated using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as reference gene. In this collection of 143 samples, the p21 alt-a expression was significantly lower in hypothermia than in chronic cardiac ischemic heart disease with (P < .001) or without (P < .001) acute myocardial infarction and in other cardiac and respiratory disease deaths (P < .000). Chronic ischemic heart disease in hypothermia cases did not increase the expression. The p21 alt-a expression did not correlate with postmortem interval, quality of RNA or with the age of the deceased. The p21 alt-a referenced to GAPDH expression in cadaver myocardium has apparent potential as a marker distinguishing between hypothermia and cardiac/respiratory diseases as causes of death.