Frequency of Selected Single Nucleotide Polymorphisms in Phase With the Mutant and Wild-Type HTT Alleles in Huntington Disease Gene Expansion Carriers

For participation in this epidemiological study, a single-day visit at the study site is required. Participants will be recruited from Huntington Disease clinics, and they will be asked to answer questions regarding their demographics, including sex, age, race and ethnicity, and their medical and medication history. At the end of the visit, a blood sample will be drawn to allow testing with a sequencing assay that is specifically designed for phasing single nucleotide polymorphisms (SNPs) on the wild-type Huntington (wtHTT) and mutant Huntington (mHTT) alleles.