@article {10568,
	title = {Common variants in CLDN14 are associated with differential excretion of magnesium over calcium in urine.},
	journal = {Pflugers Arch},
	volume = {469},
	year = {2017},
	month = {2017 01},
	pages = {91-103},
	abstract = {<p>The nature and importance of genetic factors regulating the differential handling of Ca and Mg by the renal tubule in the general population are poorly defined. We conducted a genome-wide meta-analysis of urinary magnesium-to-calcium ratio to identify associated common genetic variants. We included 9320 adults of European descent from four genetic isolates and three urban cohorts. Urinary magnesium and calcium concentrations were measured centrally in spot urine, and each study conducted linear regression analysis of urinary magnesium-to-calcium ratio on ~2.5 million single-nucleotide polymorphisms (SNPs) using an additive model. We investigated, in mouse, the renal expression profile of the top candidate gene and its variation upon changes in dietary magnesium. The genome-wide analysis evidenced a top locus (rs172639, p~=~1.7~{\texttimes}~10), encompassing CLDN14, the gene coding for claudin-14, that was genome-wide significant when using urinary magnesium-to-calcium ratio, but not either one taken separately. In mouse, claudin-14 is expressed in the distal nephron segments specifically handling magnesium, and its expression is regulated by chronic changes in dietary magnesium content. A genome-wide approach identified common variants in the CLDN14 gene exerting a robust influence on the differential excretion of Mg over Ca in urine. These data highlight the power of urinary electrolyte ratios to unravel genetic determinants of renal tubular function. Coupled with mouse experiments, these results support a major role for claudin-14, a gene associated with kidney stones, in the differential paracellular handling of divalent cations by the renal tubule.</p>},
	keywords = {Animals, Calcium, Claudins, Humans, Kidney Tubules, Magnesium, Polymorphism, Single Nucleotide, Urine},
	issn = {1432-2013},
	doi = {10.1007/s00424-016-1913-7},
	author = {Corre, Tanguy and Olinger, Eric and Harris, Sarah E and Traglia, Michela and Ulivi, Sheila and Lenarduzzi, Stefania and Belge, Hendrica and Youhanna, Sonia and Tokonami, Natsuko and Bonny, Olivier and Houillier, Pascal and Polasek, Ozren and Deary, Ian J and Starr, John M and Toniolo, Daniela and Gasparini, Paolo and Vollenweider, Peter and Hayward, Caroline and Bochud, Murielle and Devuyst, Olivier}
}
@article {3506,
	title = {Common variants in UMOD associate with urinary uromodulin levels: a meta-analysis.},
	journal = {J Am Soc Nephrol},
	volume = {25},
	year = {2014},
	month = {2014 Aug},
	pages = {1869-82},
	abstract = {<p>Uromodulin is expressed exclusively in the thick ascending limb and is the most abundant protein excreted in normal urine. Variants in UMOD, which encodes uromodulin, are associated with renal function, and urinary uromodulin levels may be a biomarker for kidney disease. However, the genetic factors regulating uromodulin excretion are unknown. We conducted a meta-analysis of urinary uromodulin levels to identify associated common genetic variants in the general population. We included 10,884 individuals of European descent from three genetic isolates and three urban cohorts. Each study measured uromodulin indexed to creatinine and conducted linear regression analysis of approximately 2.5 million single nucleotide polymorphisms using an additive model. We also tested whether variants in genes expressed in the thick ascending limb associate with uromodulin levels. rs12917707, located near UMOD and previously associated with renal function and CKD, had the strongest association with urinary uromodulin levels (P<0.001). In all cohorts, carriers of a G allele of this variant had higher uromodulin levels than noncarriers did (geometric means 10.24, 14.05, and 17.67 μg/g creatinine for zero, one, or two copies of the G allele). rs12446492 in the adjacent gene PDILT (protein disulfide isomerase-like, testis expressed) also reached genome-wide significance (P<0.001). Regarding genes expressed in the thick ascending limb, variants in KCNJ1, SORL1, and CAB39 associated with urinary uromodulin levels. These data indicate that common variants in the UMOD promoter region may influence urinary uromodulin levels. They also provide insights into uromodulin biology and the association of UMOD variants with renal function.</p>},
	keywords = {Creatinine, European Continental Ancestry Group, Genetic Variation, Humans, Polymorphism, Single Nucleotide, Uromodulin},
	issn = {1533-3450},
	doi = {10.1681/ASN.2013070781},
	author = {Olden, Matthias and Corre, Tanguy and Hayward, Caroline and Toniolo, Daniela and Ulivi, Sheila and Gasparini, Paolo and Pistis, Giorgio and Hwang, Shih-Jen and Bergmann, Sven and Campbell, Harry and Cocca, Massimiliano and Gandin, Ilaria and Girotto, Giorgia and Glaudemans, Bob and Hastie, Nicholas D and Loffing, Johannes and Polasek, Ozren and Rampoldi, Luca and Rudan, Igor and Sala, Cinzia and Traglia, Michela and Vollenweider, Peter and Vuckovic, Dragana and Youhanna, Sonia and Weber, Julien and Wright, Alan F and Kutalik, Zolt{\'a}n and Bochud, Murielle and Fox, Caroline S and Devuyst, Olivier}
}
