Parkinsonism and Lysosomal Storage Disorders share etiology
5 March 2012
There are several genes in which we now know that mutations cause Parkinson's disease (PD). These range from fairly frequent mutations, like those in LRRK2, to rarer ones such as those in SNCA.
One of the rare genes is ATP13A2, known to cause Kufor-Rakeb syndrome (KRS), a form of autosomal recessive hereditary parkinsonism with dementia and juvenile onset. Although little is known about the function of this gene, it is suspected to act in the lysosomal membrane, and to be responsible for the maintenance of lysosomal pH. The lysosomal pathway has, in the last few years, attracted interest as a novel mechanism involved in the pathogenesis of PD, following not only the identification of ATP13A2 mutations, but also the risk conferred by GBA mutations for the development of this disorder.
A team of researchers led by Drs. Rita Guerreiro and Jose Bras at UCL has identified mutations in ATP13A2 as a cause of a separate disease entity called Neuronal Ceroid-Lipofuscinosis (NCL) in a large family from Belgium.
Figure: Identification of a homozygous mutation in ATP13A2.
NCLs are a clinically and genetically heterogeneous group of neurodegenerative disorders, characterized by the intracellular accumulation of autofluorescent lipopigment storage material. It is well known that the lysosome plays a pivotal role in these disorders.
These results show undisputable evidence that the lysosomal pathway plays a role in the pathogenesis of parkinsonian phenotypes and further suggest that KRS and NCL may share pathobiological features.
Mutation of the Parkinsonism Gene ATP13A2 Causes Neuronal Ceroid-Lipofuscinosis, Hum. Mol. Genet., 2 March 2012, doi: 10.1093/hmg/dds089