CHCHD2 and Parkinson disease: Next, Funayama et al. (2015) expanded their sample and identified two other mutations in CHCHD2 that may be associated with PD in 340 patients with familial PD in Japan: c.434G > A (p.Arg145Gln) and c.300 + 5G > A; and a single and leotide polymorphism in the CHCHD2 gene was found in 517 patients with sporadic PD c.- 9T > G (rs10043) and Pro2Leu (c.5C > T; rs142444896), which increased the risk of developing sporadic PD in the Japanese population by 2.51-fold and 4.96-fold, respectively.