DDC and Menkes disease: In the MD group, the transcript levels of TPH2 and DDC genes were significantly decreased, and the transcript levels of PLA2G12A, LACT, and PLA2G6 related to GP metabolism were significantly increased, and the TNF-α, IL-6, and IL-1β genes were obviously enhanced, compared to the CN group (p < 0.05 or p < 0.01).