Objective To describe atypical longitudinal disease progression in Huntington’s disease (HD).
Subjects and methods We selected two HD subjects from a cohort of 104 Italian patients participating in the REGISTRY-Enroll-HD study.
Patient 1 is a 66 year-old man presenting depressive symptoms at age 46. First motor symptoms, noticed at age 51 (9 year later than expected from his CAG length), were mild eye movement defects and difficulties in tongue protrusion. He had very few choreic movements. Genetic test showed 20/45 CAG repeats. At age 56 UHDRS-TMS was 15 and TFC 11. In this subject both motor and cognitive impairment progressed very slowly during follow-up. After 10-year UHDRS-TMS was 28 and TFC 5. The change per year in the cognitive tests were: Symbol-Digit-Modalities-Test 0/y (baseline = 20); Verbal Fluency −0.3/year; Color-Naming −3.6/year; Word-Reading +0.7/year; and Stroop-Interferences −0.6/year. Patient 2 is a 59 year-old man, who presented motor symptoms at age 49 (11 years earlier than expected). At baseline TFC was 13 and UHDRS-TMS was 9. Genetic test showed 19/40 CAG repeats. After 10 years UHDRS-TMS was 18 and TFC 10. Cognitive tests are available only for the last 6 years of follow-up. The changes per year were: Symbol-Digit-Modalities-Test −2.3/year (baseline = 26); Verbal Fluency −1/year; Color-Naming −14.3/year; Word-Reading −2.8/year, and Stroop-Interferences −4.2/year. For both patients volumetric brain MRI and multi-tissue DNA analyses are performed.
Conclusion The identification of HD individuals with atypically mild motor and/or cognitive progression may allow the study of possible genetic/epigenetic modifying factor/s significantly slowing the clinical disease progression.
- Disease progression