Submitted to: Encyclopedia of Genetics
Publication Type: Book / Chapter
Publication Acceptance Date: January 12, 2012
Publication Date: N/A
Insulin-like growth factor 2 (IGF2) is a peptide hormone regulating various cellular processes such as proliferation and apoptosis. IGF2 is vital to embryo development. The IGF2 locus covers approximately 150-kb genomic region on human chromosome 11, containing two imprinted genes, IGF2 and H19, shared enhancers, and cis-acting regulatory elements, such as the imprinting control region (ICR). The IGF2 gene is paternally imprinted while H19 is maternally imprinted. Methylation in ICR allows the downstream enhancers to activate the IGF2 gene. If unmethylated, expression of IGF2 is suppressed, but H19 is expressed. Failure to establish imprinting correctly or alterations in this locus have important pathological implications. A disruption in normal regulation and control of the IGF2 locus results in diseases, including greater than 20 tumor types as well as growth imbalance and mental disorders.