The prevalence of Huntington's disease (HD) in China is debated; we have therefore reviewed available data and examined patients at two centres. A review of the Chinese literature on HD has found 80 studies involving 243 patients, 82.0% of which were from provinces in North China, 97.1% had a family history and paternal was greater than maternal inheritance (64.6% vs 35.4%). Mean onset age of HD was 35.2±11.5 years and duration to death was 11.6±5.6 years. Onset was more often abnormal movement accounted (47.7%), followed by psychiatric symptoms (18.1%) and cognitive (2.1%), increasing with disease progression to 99.5%, and 39.2% and 69.8%, respectively. Of the reported patients, only 22 were confirmed by molecular testing. This review of the literature demonstrates that indeed the disease is present in China, possibly more frequently in northern regions. However, there are major uncertainties linked to the data as only a small proportion of the cases have been diagnosed at the molecular level. We have therefore started to build cohorts with prospective patient examination using standardised protocols and reports on data of the first two centres in China. In Chengdu, 25 patients from different families were diagnosed with increased triplet numbers ranging from 40 to 55, their mean age at onset was 45 years and 76% had motor presentation. In Gangzhou, 17 adults from eight families had triplet repeats form 41 to 51 with a mean age of onset of 42 years. The initial symptoms were motor in 88% of the cases. There is a clear correlation of age at onset and triplet repeat numbers. Neither of the studies disclosed inter-racial marriage with Caucasian. Compared with the literature on Caucasian, the data seem to indicate a higher number of young onset cases, a shorter life span with more rapid progression and a lower frequency of cognitive impairment at presentation. Larger cohorts, including from other centres, will offer more precise conclusions about phenotype. This should allow comparisons with Caucasian cohorts, including investigations of genetic modifiers.
- clinical presentation