Figure 1.

Human chromosome 15q11–13 region. Paternal and maternal chromosome 15q11–13 regions around the Angelman syndrome imprinting center (AS-IC) and Prader–Willi syndrome imprinting center (PWS-IC) are presented. Paternally expressed genes are indicated as deep blue, maternally expressed genes are indicated in red, and genes expressed from both parental alleles are indicated as pink. Transcription orientation is noted with arrows. Class I and class II deletions are indicated as horizontal lines. BP, breakpoint cluster region; CH3, methylation; snoRNA, small nucleolar RNA; SNRPN, small nuclear ribonucleoprotein-associated protein N; UBE3A, ubiquitin–protein ligase E3A.