Nalls et al. (2019) used SKAT-O in their meta GWAS to identify genes with two or more rare coding variants, and 7 significant genes: LRRK2, GBA, CATSPER3, LAMB2, LOC442028, NFKB2 and SCARB2. SKAT has also been used to study the association of genetic variants to individual phenotypic characteristics of PD, including motor and cognitive functions (Markopoulou et al., 2021). This evidence concerns the gene LRRK2 and Parkinson disease.