**5. Conclusions**

In this study, patients with juvenile-onset Huntington's Disease (JOHD) exhibited significant behavioral problems relative to gene non-expanded (GNE) counterparts. Those participants with longer CAG repeats (earlier age of onset) had fewer behavioral problems compared to those with relatively shorter repeats (later age of onset). Lack of insight may have prohibited adult patients with JOHD from providing reliable assessments of their behavioral problems. Further research should be conducted with larger samples to create a JOHD-specific behavioral rating measure including both self and proxy measures that may be used as markers for clinical trials and treatments.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2076-3425/10/8/543/s1, Table S1: BRIEF subscale statistics, Table S2: PBS subscale statistics, Table S3: BRIEF-Adult subscale statistics.

**Author Contributions:** Conceptualization, K.E.L., E.v.d.P. and P.N.; methodology, K.E.L., E.v.d.P., and P.N.; software, K.E.L. and E.v.d.P.; validation, K.E.L., E.v.d.P., and P.N.; formal analysis, K.E.L. and E.v.d.P.; investigation, A.M.C., E.E., E.M. and P.E.-P.; resources, P.N.; data curation, A.M.C., E.E., E.M., P.E.-P.; writing—original draft preparation, K.E.L., A.M.C., E.v.d.P.; writing—review and editing, A.L.C., E.E., E.M., P.E.-P. and P.N.; visualization, K.E.L. and E.v.d.P.; supervision, E.v.d.P. and P.N.; project administration, P.N.; funding acquisition, P.N. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was supported by National Institute of Neurological Disorders and Stroke (NINDS; R01NS055903). The APC was funded by National Institute of Neurological Disorders and Stroke (NINDS; R01NS055903).

**Acknowledgments:** In this section you can acknowledge any support given which is not covered by the author contribution or funding sections. This may include administrative and technical support, or donations in kind (e.g., materials used for experiments).

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
