THRA and Pallister-Hall syndrome: In this study, our aim is to investigate the alteration of cardiac gene expression (ACTC1, MHCα, MHCβ, RYR2, SERCA2, THRα, THRβ, and troponin I) responsive to thyroid hormones in the broiler chickens exposed to low temperature that progressively indicated the signs of PHS and ascites (Davis and Davis, 2002; Dillmann, 2002; Kahaly and Dillmann, 2005).