P-51 Deep Phenotyping of Huntington Diseases (HD)

Methods: This is an exploratory, comparative, etiological, longitudinal, prospective, single-centre observational study based on the active file of patients followed up at the centre for Rare Diseases in Martinique. Two groups of patients will be compared: patients with a confirmed diagnosis of HD VS Patients with a confirmed diagnosis of HDL2. The patients will receive the same treatment. The research will involve collecting clinical, paraclinical and biological indicators from patients at inclusion, at 12 months and at 24 months. Blood samples will be taken to build up a DNA and plasma libraries. Biomarker assays will be performed. Urine samples collected at the different stages of the research will be kept for later study. Similarly, skin biopsies will be used to preserve cells for induced pluripotent stem cells.

Results: This study is innovative in the context of Huntington like disease type 2 (HDL2), associated with JPH3 gene. For the first time, it will describe known biomarkers of HD in HDL2. This observational and descriptive study will help to add to the literature and to envisage new physiopathological and even therapeutic hypotheses.

Conclusion: Given the lack of data on clinical markers that discriminate between HD and HDL2, deep-phenotyping of our cohort appears to be a major challenge for researching and comparing sub-phenotypic characteristics with a view to improving our knowledge of Huntington’s disease, in particular HDL2. It seems relevant to compare biomarkers between HD and HDL2 patients, because biomarkers known and well-described in HD, to date, are not in HDL2.