Fig. 2

Exemplary schematic of four molecular subtypes in genetic imprinting disorders. The pathological conditions affecting the expression pattern of one maternal-inherited imprinted gene involve chromosomal deletion, paternal uniparental disomy (UPD) (where two paternal-inherited chromosomes are present losing the maternally expressed gene copy), imprinting defect (which is resulted from epigenetic dysregulation with identical DNA sequences), and gene mutation. For clarity, the paternal and maternal homologous chromosome ideograms (in blue and pink, respectively), one paternally expressed imprinted gene (yellow hexagram), and one maternally expressed imprinted gene (red square) are shown, respectively