TARDBP and amyotrophic lateral sclerosis: Cryptic exons reflect abnormal RNA splicing, leading to the inclusion of an intronic sequence into a mature mRNA transcript.67 Cryptic exons resulting from TDP-43 loss of function can be detected in tissue from patients with ALS or frontotemporal dementia.67,71,69,70,68,94; however, the susceptibility of RNA to degradation might make the clinical translation of these data challenging.