TMEM175 and Parkinson disease: Considering the polygenic inheritance associated with PD, disclosed in our previous study [8], we identified 4 patients carrying one mutation in TMEM175 and one pathogenic mutation in GBA (p.N409S or H294Q); three patients carrying one mutation in TMEM175 and one pathogenic mutation in PARK2, PARK7, and PINK1 respectively; and 8 patients carrying one mutation in TMEM175 and one rare deleterious variant in other PD candidate genes such as AIMP2, KIF24, MAN2C1, SNCAIP, SPTBN1, and TVP23A. Eight PD patients carried a single deleterious variant in TMEM175 alone (Table 4, Fig. 4).