A recent study in FTD/ALS and synucleinopathies showed a frequency of low‐penetrance (36–39) HTT repeat expansions of 0.20, 0.19%, 0.3% in FTD/ALS, LBD, PD, respectively, like that the observed in healthy controls (0.22%) suggesting that low‐penetrance HTT repeat expansions have no effect in TDP‐43 or α‐synuclein proteinopathies. This evidence concerns the gene TARDBP and Parkinson disease.