Supplementing the alterations in PGC-1α expression in HD, Johri et al. reported decreased protein level of the functionally active N-truncated splice variant of PGC-1α (NT-PGC-1α) in the striatum of low-grade HD patients and young asymptomatic transgenic N171-82Q and R6/2 HD mice, whereas its level was found to be elevated in high-grade HD patients and in older symptomatic transgenic HD mice [156]. This evidence concerns the gene PPARGC1A and ring chromosome 6.