Inactivating Mutations in <i>NPC1L1</i> and Protection from Coronary Heart Disease
Authors: Nathan O Stitziel, Hong-Hee Won, Alanna C Morrison, Gina M Peloso, Ron Do, Leslie A Lange, Pierre Fontanillas, Namrata Gupta, Stefano Duga, Anuj Goel, Martin Farrall, Danish Saleheen, Paola Ferrario, Inke König, Rosanna Asselta, Piera A Merlini, Nicola Marziliano, Maria Francesca Notarangelo, Ursula Schick, Paul Auer, Themistocles L Assimes, Muredach Reilly, Robert Wilensky, Daniel J Rader, G Kees Hovingh, Thomas Meitinger, Thorsten Kessler, Adnan Kastrati, Karl-Ludwig Laugwitz, David Siscovick, Jerome I Rotter, Stanely L Hazen, Russell Tracy, Sharon Cresci, John Spertus, Rebecca Jackson, Stephen M Schwartz, Pradeep Natarajan, Jacy Crosby, Donna Muzny, Christie Ballantyne, Stephen S Rich, Christopher J O'Donnell, Goncalo Abecasis, Shamil Sunaev, Deborah A Nickerson, Julie E Buring, Paul M Ridker, Daniel I Chasman, Erin Austin, Iftikhar J Kullo, Peter E Weeke, Christian M Shaffer, Lisa A Bastarache, Joshua C Denny, Dan M Roden, Colin Palmer, Panos Deloukas, Dan-Yu Lin, Zheng-zheng Tang, Jeanette Erdmann, Heribert Schunkert, John Danesh, Jaume Marrugat, Roberto Elosua, Diego Ardissino, Ruth McPherson, Hugh Watkins, Alex P Reiner, James G Wilson, David Altshuler, Richard A Gibbs, Eric S Lander, Eric Boerwinkle, Stacey Gabriel, Sekar Kathiresan
Journal: New England Journal of Medicine (2014)

Ezetimibe lowers plasma levels of low-density lipoprotein (LDL) cholesterol by inhibiting the activity of the Niemann-Pick C1-like 1 (NPC1L1) protein. However, whether such inhibition reduces the risk of coronary heart disease is not known. Human mutations that inactivate a gene encoding a drug target can mimic the action of an inhibitory drug and thus can be used to infer potential effects of that drug.We sequenced the exons of NPC1L1 in 7364 patients with coronary heart disease and in 14,728 controls without such disease who were of European, African, or South Asian ancestry. We identified carriers of inactivating mutations (nonsense, splice-site, or frameshift mutations). In addition, we genotyped a specific inactivating mutation (p.Arg406X) in 22,590 patients with coronary heart disease and in 68,412 controls. We tested the association between the presence of an inactivating mutation and both plasma lipid levels and the risk of coronary heart disease.With sequencing, we identified 15 distinct NPC1L1 inactivating mutations; approximately 1 in every 650 persons was a heterozygous carrier for 1 of these mutations. Heterozygous carriers of NPC1L1 inactivating mutations had a mean LDL cholesterol level that was 12 mg per deciliter (0.31 mmol per liter) lower than that in noncarriers (P=0.04). Carrier status was associated with a relative reduction of 53% in the risk of coronary heart disease (odds ratio for carriers, 0.47; 95% confidence interval, 0.25 to 0.87; P=0.008). In total, only 11 of 29,954 patients with coronary heart disease had an inactivating mutation (carrier frequency, 0.04%) in contrast to 71 of 83,140 controls (carrier frequency, 0.09%).Naturally occurring mutations that disrupt NPC1L1 function were found to be associated with reduced plasma LDL cholesterol levels and a reduced risk of coronary heart disease. (Funded by the National Institutes of Health and others.).