SYNJ1 and Parkinson disease: Recently identified loci possibly also causing recessive PD forms are hemizygous deletions of the chromosome 22 region q11.2 [37], and rare variants in the synaptojanin 1 (SYNJ1) [38,39], DnaJ heat shock protein family (Hsp40) member C6 (DNAJC6) [40], podocalyxin like (PODXL) [41], and peptidyl-tRNA hydrolase domain containing 1 gene (PTRHD1) [42].