title: Detection of mutations in KLHL3 and CUL3 in families with FHHt (familial hyperkalaemic hypertension or Gordon's syndrome).
abstract: The study of families with rare inherited forms of hypo- and hyper-tension has been one of the most successful strategies to probe the molecular pathophysiology of blood pressure control and has revealed dysregulation of distal nephron Na+ reabsorption to be a common mechanism. FHHt (familial hyperkalaemic hypertension; also known as Gordon's syndrome) is a salt-dependent form of hypertension caused by mutations in the regulators of the thiazide-sensitive Na+-Cl- co-transporter NCC [also known as SLC12A3 (solute carrier family 12 member 3)] and is effectively treated by thiazide diuretics and/or dietary salt restriction. Variation in at least four genes can cause FHHt, including WNK1 [With No lysine (=K) 1] and WNK4, KLHL3 (kelch-like family member 3), and CUL3 (cullin 3). In the present study we have identified novel disease-causing variants in CUL3 and KLHL3 segregating in 63% of the pedigrees with previously unexplained FHHt, confirming the importance of these recently described FHHt genes. We have demonstrated conclusively, in two unrelated affected individuals, that rare intronic variants in CUL3 cause the skipping of exon 9 as has been proposed previously. KLHL3 variants all occur in kelch-repeat domains and so probably disrupt WNK complex binding. We have found no evidence of any plausible disease-causing variants within SLC4A8 (an alternative thiazide-sensitive sodium transporter) in this population. The results of the present study support the existing evidence that the CUL3 and KLHL3 gene products are physiologically important regulators of thiazide-sensitive distal nephron NaCl reabsorption, and hence potentially interesting novel anti-hypertensive drug targets. As a third of our non-WNK FHHt families do not have plausible CUL3 or KLHL3 variants, there are probably additional, as yet undiscovered, regulators of the thiazide-sensitive pathways.
authors.affiliation: *Division of Therapeutics and Molecular Medicine, University of Nottingham, Nottingham, U.K.
authors.forename: Mark
authors.initials: M
authors.lastname: Glover
authors.forename: James S
authors.initials: JS
authors.lastname: Ware
authors.affiliation: *Division of Therapeutics and Molecular Medicine, University of Nottingham, Nottingham, U.K.
authors.forename: Amanda
authors.initials: A
authors.lastname: Henry
authors.affiliation: §Endocrine Hypertension Research Centre, University of Queensland School of Medicine, Brisbane, Australia.
authors.forename: Martin
authors.initials: M
authors.lastname: Wolley
authors.affiliation: †NIHR Biomedical Research Unit in Cardiovascular Disease at Royal Brompton and Harefield NHS Foundation Trust and Imperial College London, London, U.K.
authors.forename: Roddy
authors.initials: R
authors.lastname: Walsh
authors.affiliation: ¶Genetic Epidemiology Group, University of Leicester, Leicester, U.K.
authors.forename: Louise V
authors.initials: LV
authors.lastname: Wain
authors.affiliation: §Endocrine Hypertension Research Centre, University of Queensland School of Medicine, Brisbane, Australia.
authors.forename: Shengxin
authors.initials: S
authors.lastname: Xu
authors.affiliation: ∥Paediatric Nephrology Department, Great Ormond Street Hospital for Children, London, U.K.
authors.forename: William G
authors.initials: WG
authors.lastname: Van't Hoff
authors.affiliation: ¶Genetic Epidemiology Group, University of Leicester, Leicester, U.K.
authors.forename: Martin D
authors.initials: MD
authors.lastname: Tobin
authors.affiliation: *Division of Therapeutics and Molecular Medicine, University of Nottingham, Nottingham, U.K.
authors.forename: Ian P
authors.initials: IP
authors.lastname: Hall
authors.forename: Stuart
authors.initials: S
authors.lastname: Cook
authors.affiliation: §Endocrine Hypertension Research Centre, University of Queensland School of Medicine, Brisbane, Australia.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Gordon
authors.affiliation: §Endocrine Hypertension Research Centre, University of Queensland School of Medicine, Brisbane, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Stowasser
authors.affiliation: ‡‡Clinical Pharmacology Unit, University of Cambridge, Cambridge, U.K.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: O'Shaughnessy
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D017398:Alternative Splicing / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics*; D020090:Chromosome Segregation / Q000235:genetics; D044842:Cullin Proteins / Q000235:genetics*; D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics; D005190:Family; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008840:Microfilament Proteins; D009154:Mutation / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D011546:Pseudohypoaldosteronism / Q000235:genetics*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C503645:CUL3 protein, human; D002352:Carrier Proteins; D044842:Cullin Proteins; C489837:KLHL3 protein, human; D008840:Microfilament Proteins