CHCHD2 and Parkinson disease: In contrast, even though most patients with T61I CHCHD2-associated PD to date have not presented until their 50s (28), and idiopathic PD typically starts after age 50 (76), T61I CHCHD2 mice develop profound CHCHD2 aggregation, resembling the aggregation reported in a patient with CHCHD2 PD (29).