1. Publications

A Loss-of-Function Splice Acceptor Variant in IGF2 Is Protective for Type 2 Diabetes

Josep M Mercader, Rachel G Liao, Avery D Bell, Zachary Dymek, Karol Estrada, Taru Tukiainen, Alicia Huerta-Chagoya, Hortensia Moreno-Macías, Kathleen A Jablonski, Robert L Hanson, Geoffrey A Walford, Ignasi Moran, Ling Chen, Vineeta Agarwala, María Luisa Ordoñez-Sánchez, Rosario Rodríguez-Guillen, Maribel Rodríguez-Torres, Yayoi Segura-Kato, Humberto García-Ortiz, Federico Centeno-Cruz, Francisco Barajas-Olmos, Lizz Caulkins, Sobha Puppala, Pierre Fontanillas, Amy L Williams, Sílvia Bonàs-Guarch, Chris Hartl, Stephan Ripke, Diabetes Prevention Program Research Group; Katherine Tooley, Jacqueline Lane, Carlos Zerrweck, Angélica Martínez-Hernández, Emilio J Córdova, Elvia Mendoza-Caamal, Cecilia Contreras-Cubas, María E González-Villalpando, Ivette Cruz-Bautista, Liliana Muñoz-Hernández, Donaji Gómez-Velasco, Ulises Alvirde, Brian E Henderson, Lynne R Wilkens, Loic Le Marchand, Olimpia Arellano-Campos, Laura Riba, Maegan Harden, Broad Genomics Platform; Stacey Gabriel, T2D-GENES Consortium; Hanna E Abboud, Maria L Cortes, Cristina Revilla-Monsalve, Sergio Islas-Andrade, Xavier Soberon, Joanne E Curran, Christopher P Jenkinson, Ralph A DeFronzo, Donna M Lehman, Craig L Hanis, Graeme I Bell, Michael Boehnke, John Blangero, Ravindranath Duggirala, Richa Saxena, Daniel MacArthur, Jorge Ferrer, Steven A McCarroll, David Torrents, William C Knowler, Leslie J Baier, Noel Burtt, Clicerio González-Villalpando, Christopher A Haiman, Carlos A Aguilar-Salinas, Teresa Tusié-Luna, Jason Flannick, Suzanne B R Jacobs, Lorena Orozco, David Altshuler, Jose C Florez, SIGMA T2D Genetics Consortium.
Diabetes. 2017-08-24;66(11):2903-2914.
Abstract
Type 2 diabetes (T2D) affects more than 415 million people worldwide, and its costs to the health care system continue to rise. To identify common or rare genetic variation with potential therapeutic implications for T2D, we analyzed and replicated genome-wide protein coding variation in a total of 8,227 individuals with T2D and 12,966 individuals without T2D of Latino descent. We identified a novel genetic variant in the IGF2 gene associated with ∼20% reduced risk for T2D. This variant, which has an allele frequency of 17% in the Mexican population but is rare in Europe, prevents splicing between IGF2 exons 1 and 2. We show in vitro and in human liver and adipose tissue that the variant is associated with a specific, allele-dosage-dependent reduction in the expression of IGF2 isoform 2. In individuals who do not carry the protective allele, expression of IGF2 isoform 2 in adipose is positively correlated with both incidence of T2D and increased plasma glycated hemoglobin in individuals without T2D, providing support that the protective effects are mediated by reductions in IGF2 isoform 2. Broad phenotypic examination of carriers of the protective variant revealed no association with other disease states or impaired reproductive health. These findings suggest that reducing IGF2 isoform 2 expression in relevant tissues has potential as a new therapeutic strategy for T2D, even beyond the Latin American population, with no major adverse effects on health or reproduction.
Consortium data used in this publication
The genotype and phenotype data are available in the Database of Genotypes and Phenotypes (dbGaP) under accession numbers phs001375, phs001388, phs001393, and phs001429.