Hypertension and Acid-Base/Electrolyte Disorders Patients With Biallelic Mutations in the Chloride Channel Gene CLCNKB: Long-Term Management and Outcome

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 (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). Conclusion: 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. Am J Kidney Dis 49:91-98. © 2006 by the National Kidney Foundation, Inc.