Dominant forms of PD
Although gain-of-function mutations in SNCA/PARK1/4 and LRRK2/
PARK8 clearly cause AD PD, the effects of other dominant genes,
such as Ubiquitin-C terminal hydrolase L1 (UCHL1/PARK5), GRB10-
interacting GYF protein 2 (GIGYF2/PARK11), Omi/Htra2 (PARK13),
remain controversial; they have either not been replicated in other
studies (UCHL1, GIGYF2) or appear to be risk factors (HTRA2).
After identification of SNCA, a-synuclein was found to be the
major fibrillar component of Lewy bodies, the pathological hallmark
of familial and sporadic PD [5]. Two other SNCA point mutations,
as well as whole gene duplications and triplications [6], have