["Oxidative stress and iron deposition is related to Parkinson's disease (PD). Heme oxygenase 2 (HMOX2) catalyzes the cleavage of the heme ring to form biliverdin with release of iron and carbon monoxide. This study aims to analyze variations in the HMOX2 gene in patients with PD.", 'We mapped four single nucleotide polymorphisms (SNPs) and copy number variations of the HMOX2 gene in 691 patients with PD and 747 healthy individuals.', 'We identified a highly homogeneous association of the HMOX2 SNP rs2270363 homozygous G/G genotype with patients with classical PD phenotype compared with healthy individuals. We identified three patients with PD and two control individuals with a single copy of the HMOX2 gene. No individuals with zero or more than two gene copies were identified.'] Is a polymorphism located at an ATG transcription start site of the heme oxygenase-2 gene associated with classical Parkinson 's disease?