NDN and Prader-Willi syndrome: Genes and transcripts included in the area from the proximal 15q11.2 breakpoints BP1 and the distal 15q13 breakpoint BP3 are TUBGCP5, CYFIP1, NIPA1, NIPA2, MRKN3, MAGEL2, NDN, NIPAP1, SNURF-SNRPN, non-coding RNAs (SNORDs), UBE3A, ATP10A, GABRB3, GABRA5, GABRG3, OCA2, and HERC2. Imprinted MRKN3, MAGEL2, NDN, NIPAP1, and SNURF-SNRPN genes are paternally expressed and when disturbed may cause features of PWS [e.g., (10)].