POLG1 polyglutamine tract variants associated with Parkinson's disease

A possible role of allelic variation of the mitochondrial DNA polymerase gamma ( POLG1) gene in Parkinson's disease (PD) has been suggested. First, POLG1 missense mutations have been found in patients with familial parkinsonism and mitochondrial myopathy. Second, increased frequency of rare alleles of the POLG1 CAG-repeat (poly-Q) has been found in Finnish idiopathic apparently sporadic PD patients, but conflicting reports exist. The POLG1 poly-Q exhibits one major allele with 10 repeats (10Q, frequency ≥80%) and several less common alleles such as 11Q (frequency 6–9%), 6Q–9Q and 12Q–14Q (frequencies