Mutation of the Mg2+ transporter SLC41A1 results in a nephronophthisis-like phenotype

Toby W. Hurd, Edgar A. Otto, Eikan Mishima, Heon Yung Gee, Hana Inoue, Masato Inazu, Hideomi Yamada, Jan Halbritter, George Seki, Masato Konishi, Weibin Zhou, Tsutomo Yamane, Satoshi Murakami, Gianluca Caridi, Gianmarco Ghiggeri, Takaaki Abe, Friedhelm Hildebrandt

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32 Citations (Scopus)

Abstract

Nephronophthisis (NPHP)-related ciliopathies are recessive, single-gene disorders that collectively make up themost common genetic cause of CKD in the first three decades of life.Mutations in 1 of the 15 known NPHP genes explain less than half of all cases with this phenotype, however, and the recently identified genetic causes are exceedingly rare. As a result, a strategy to identify single-gene causes of NPHP-related ciliopathies in single affected families is needed. Although whole-exome resequencing facilitates the identification of disease genes, the large number of detected genetic variants hampers its use. Here, we overcome this limitation by combining homozygosity mapping with whole-exome resequencing in a sibling pair with an NPHP-related ciliopathy.Whole-exome capture revealed a homozygous splice acceptor sitemutation (c.698G.T) in the renalMg2+ transporter SLC41A1. Thismutation resulted in skipping of exon 6 of SLC41A1, resulting in an in-frame deletion of a transmembrane helix. Transfection of cells with wild-type or mutant SLC41A1 revealed that deletion of exon 6 completely blocks the Mg 2+ transport function of SLC41A1. Furthermore, in normal human kidney tissue, endogenous SLC41A1 specifically localized to renal tubules situated at the corticomedullary boundary, consistent with the region of cystogenesis observed in NPHP and related ciliopathies. Last, morpholino-mediated knockdown of slc41a1 expression in zebrafish resulted in ventral body curvature, hydrocephalus, and cystic kidneys, similar to the effects of knocking down other NPHP genes. Taken together, these data suggest that defects in the maintenance of renal Mg2+ homeostasis may lead to tubular defects that result in a phenotype similar to NPHP.

Original languageEnglish
Pages (from-to)967-977
Number of pages11
JournalJournal of the American Society of Nephrology
Volume24
Issue number6
DOIs
Publication statusPublished - 2013 May 31

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All Science Journal Classification (ASJC) codes

  • Nephrology

Cite this

Hurd, T. W., Otto, E. A., Mishima, E., Gee, H. Y., Inoue, H., Inazu, M., Yamada, H., Halbritter, J., Seki, G., Konishi, M., Zhou, W., Yamane, T., Murakami, S., Caridi, G., Ghiggeri, G., Abe, T., & Hildebrandt, F. (2013). Mutation of the Mg2+ transporter SLC41A1 results in a nephronophthisis-like phenotype. Journal of the American Society of Nephrology, 24(6), 967-977. https://doi.org/10.1681/ASN.2012101034