PHF6 and Borjeson-Forssman-Lehmann syndrome: In human disease, R-loop-mediated rDNA damage has been linked to Borjeson-Forssman-Lehmann syndrome (PHF6), Friedreich ataxia (FXN), amyotrophic lateral sclerosis type 4 (SETX), and Fragile X syndrome (FMR1), among others.