title: Patients with biallelic mutations in the chloride channel gene CLCNKB: long-term management and outcome.
abstract: BACKGROUND
  Little information on the management and long-term follow-up of patients with biallelic mutations in the chloride channel gene CLCNKB is available.
  
  
  METHODS
  Long-term follow-up was evaluated from 5.0 to 24 years (median, 14 years) after diagnosis in 13 patients with homozygous (n = 10) or compound heterozygous (n = 3) mutations.
  
  
  RESULTS
  Medical treatment at last follow-up control included supplementation with potassium in 12 patients and sodium in 2 patients and medical treatment with indomethacin in 9 patients. At the end of follow-up, body height was 2.0 standard deviation score or less in 6 patients; 2 of these patients had growth hormone deficiency. Body weight (<or=2.0 standard deviation score in 6 patients) significantly increased (P < 0.05) at the end of follow-up in comparison to values at diagnosis. Nonpostural persistent proteinuria was present in 6 patients, and 4 patients had a glomerular filtration rate less than 75 mL/min/1.73 m(2) (<1.25 mL/s).
  
  
  CONCLUSIONS
  These data show that some patients with biallelic mutations in the chloride channel gene CLCNKB tend to present with pathological proteinuria and impaired kidney function after a median follow-up of 14 years, and growth retardation is common and sometimes related to growth hormone deficiency in these patients.
authors.affiliation: Pediatric Renal Unit and Laboratory of Medical Genetics, Fondazione Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, IRCCS. a.bettinelli@ospedale.lecco.it
authors.forename: Alberto
authors.initials: A
authors.lastname: Bettinelli
authors.forename: Nicolò
authors.initials: N
authors.lastname: Borsa
authors.forename: Rosa
authors.initials: R
authors.lastname: Bellantuono
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Syrèn
authors.forename: Raffaele
authors.initials: R
authors.lastname: Calabrese
authors.forename: Alberto
authors.initials: A
authors.lastname: Edefonti
authors.forename: John
authors.initials: J
authors.lastname: Komninos
authors.forename: Marisa
authors.initials: M
authors.lastname: Santostefano
authors.forename: Luciano
authors.initials: L
authors.lastname: Beccaria
authors.forename: Ivana
authors.initials: I
authors.lastname: Pela
authors.forename: Mario G
authors.initials: MG
authors.lastname: Bianchetti
authors.forename: Silvana
authors.initials: S
authors.lastname: Tedeschi
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D001477:Bartter Syndrome / Q000188:drug therapy / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D018118:Chloride Channels / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009154:Mutation; D013997:Time Factors
chemical_list: C412733:CLCNKB protein, human; D018118:Chloride Channels