Familial progressive supranuclear palsy: a literature review.

BACKGROUND Many genes/loci associated with Parkinsonian disorders have been identified. However, the genetic causes for a number of familial forms of Parkinsonian disorders remain to be elucidated. OBJECTIVE It was the aim of this paper to review the familial progressive supranuclear palsy (PSP) cases without any known gene mutations published in the English literature. METHODS We searched the PubMed database for reports of familial PSP cases without known mutations. RESULTS We found 19 PSP families. The mean age at onset was approximately 60 years, and the mean disease duration was about 8 years. Parkinsonism and ophthalmoplegia were most frequently reported, and a vast majority of patients manifested with these two symptoms. Other symptoms such as falls, postural instability and pyramidal signs were also common. A small subset of patients transiently responded to L-dopa therapy. CONCLUSION There is an increasing number of reported familial PSP. A recently performed genome-wide association study indicated genetic factors for this condition. Furthermore, clinical, pathological and genetic investigations will open new avenues to the discovery of causative genes and new therapeutics for PSP.