Figure 4
From: Prader-Willi syndrome
Genetic classes of Prader-Willi syndrome (PWS) and their average frequencies (I: deletion, II: uniparental disomy, III: imprinting defect). Bars represent chromosome 15. P indicates the paternally inherited chromosome 15, and M indicates the maternally contributed one. Class III occurs when there is biparental inheritance, but the paternally inherited chromosome 15 is imprinted in the manner typical of the maternal chromosome 15 (i.e., relevant genes are not expressed).
