Using 35 day-differentiated mDA cells carrying common familial PD mutations in the PRKN, SNCA, LRRK2, PINK1, DNAJC6, FBXO7, SYNJ1, PARK7, VPS13C, ATP13A2 and GBA1 genes or wild-type genotypes, we prepared total RNA, poly(A)-mRNA selected and then generated random-primed cDNA libraries from 1–3 independently derived subclonal cell lines in technical triplicates. The gene discussed is SYNJ1; the disease is Parkinson disease.