MAPK14 and juvenile Huntington disease: Compared to younger people in subgroup of participants with higher eGFR decline rate (n = 187), hypermethylated genes in older participants involved in cellular process and regulation of gene expression and metabolism such as Huntington’s disease signaling pathway, DNA methylation and transcriptional repressing signaling pathway, P38 mitogen-activated protein kinase (MAPK) signaling pathway, cold shock domain-containing protein E1 (CSDE1) signaling pathway, and sirtuin signaling pathway (Fig. 3A).