A previous study indicated a strong association between the Pitx3 promoter and PD (p = 0.0001), as well as between EN1 and PD (p = 0.046), after genotyping nine single nucleotide polymorphisms in the entire genomic region of Pitx3 and EN1 from 365 PD patients and 418 controls [72]. Here, PITX3 is linked to Parkinson disease.