Another of our enriched motifs (motif 9) is similar to that recognized by Fmr1 (ANGGACA), which is involved in RNA trafficking and translation, and whose loss causes Fragile X syndrome (Ishizuka et al. 2002), while another motif (motif 13) is similar to that recognized by Topoisomerase 2 (Top2; TACATATGTATGTA), which is well-known for its role in DNA replication, but has also been found to play a role in transcription and insulator function (Lupo et al. 2001; Ramos et al. 2011). The gene discussed is TOP2A; the disease is fragile X syndrome.