This may result in a more profound allele-specific effect on spliceosome assembly during transcription of the H2 allele, giving rise to the large increase in 4R-tau mRNA that we observe in Huntington’s disease, especially given that SRSF6 is involved in MAPT exon 10 splicing (Yin et al., 2012) and co-localizes with mutant HTT inclusions (Fernández-Nogales et al., 2014). Here, HTT is linked to juvenile Huntington disease.