When these two isoforms were quantified in each brain tissue sample using Droplet Digital Polymerase Chain Reaction, the RPGRIP1L transcript with exon 20 spliced out was significantly decreased in the dorsolateral prefrontal cortex and hippocampus of individuals with schizophrenia and bipolar disorder risk alleles rs8050354(T) and rs7203525(T) [29]. Here, RPGRIP1L is linked to schizophrenia.