A single nucleotide polymorphism in the coding region of PGC-1α is a male-specific modifier of Huntington disease age-at-onset in a large European cohort

Background: Genetic modifiers are important clues for the identification of therapeutic targets in neurodegenerative diseases. Huntington disease (HD) is one of the most common autosomal dominant inherited neurodegenerative diseases. The clinical symptoms include motor abnormalities, cognitive decline and behavioral disturbances. Symptom onset is typically between 40 and 50 years of age, but can vary by several decades in extreme cases and this is in part determined by modifying genetic factors. The metabolic master regulator PGC-1 alpha, coded by the PPARGC1A gene, coordinates cellular respiration and was shown to play a role in neurodegenerative diseases, including HD. Methods: Using a candidate gene approach we analyzed a large European cohort (n = 1706) from the REGISTRY study for associations between PPARGC1A genotype and age at onset (AO) in HD. Results: We report that a coding variant (rs3736265) in PPARGC1A is associated with an earlier motor AO in men but not women carrying the HD mutation. Conclusions: These results further strengthen the evidence for a role of PGC-1 alpha in HD and unexpectedly suggest a gender effect.