ANRIL, a Long, Noncoding RNA, is an Unexpected Major Hotspot in GWAS

A large noncoding RNA called ANRIL (for antisense noncoding RNA in the INK4 locus) has been identified within the p15/CDKN2B-p16/CDKN2A-p14/ARF gene cluster. While the exact role of ANRIL awaited further elucidation, common disease genomewide association studies (GWAS) have surprisingly identified the ANRIL gene as a genetic susceptibility locus shared associated by coronary disease, intracranial aneurysm and also type 2 diabetes. Expression studies have confirmed the coregulation of p15/CDKN2B, p16/CDKN2A, p14/ARF, and ANRIL. Among the cluster, ANRIL expression showed the strongest association with the multiple phenotypes linked to the 9p21.3 region. More recent GWAS also identified ANRIL as a risk locus for gliomas and basal cell carcinomas in accordance with the princeps observation. Moreover, a mouse model has confirmed the pivotal role of ANRIL in regulation of CDKN2A/B expression through a cis-acting mechanism and its implication in proliferation and senescence. The implication of ANRIL in cellular aging has provided an attractive unifying hypothesis to explain its association with various susceptibility risk factors. ANRIL identification emphasizes the underestimated role of long noncoding RNAs. Many GWAS have identified trait-associated SNPs that felt in noncoding genomic regions. It is conceivable to anticipate that long, noncoding RNAs will map to many of these "gene deserts."