Bartter syndrome complicated by immune complex nephropathy. Case report and literature review.
The unusual coincidence of Bartter syndrome and C1q nephropathy is described and the literature reviewed. An African-American girl presented at 4 years of age with acute hyponatremic dehydration and failure to thrive. Persistent hypokalemic alkalosis and secondary hyperaldosteronism were found. The case was atypical for Bartter syndrome in that proteinuria (0.19 g/day) was present. Renal biopsy showed juxtaglomerular hyperplasia and C1q nephropathy. Molecular analysis showed deletion of the renal chloride channel gene (CLCNKB) typical of autosomal recessive childhood Bartter syndrome. Chronic sodium and potassium chloride replacement therapy together with indomethacin normalized her metabolic status, and she experienced catch-up growth. Proteinuria persisted, however. This is the first documentation of C1q nephropathy, in mild form, complicating autosomal recessive Bartter syndrome. This case shows the importance of the renal biopsy and of molecular analysis in delineating the cause of atypical nephropathy associated with Bartter syndrome. These findings add to the evidence of a possible association between the congenital syndrome and acquired immune complex nephropathy.
Sardani
Yahya
Y
Department of Pediatrics, The University of Chicago Pritzker School of Medicine, 5839 S. Maryland Avenue, Chicago, IL 60637-1470, USA.
Qin
Kenan
K
Haas
Mark
M
Aronson
Andrew J
AJ
Rosenfield
Robert L
RL
D027321:Anion Transport Proteins / Q000235:genetics; D001477:Bartter Syndrome / Q000150:complications* / Q000235:genetics / Q000473:pathology; D002675:Child, Preschool; D018118:Chloride Channels / Q000235:genetics; D015922:Complement C1q / Q000276:immunology*; D005260:Female; D005920:Glomerular Mesangium / Q000276:immunology / Q000473:pathology; D006801:Humans; D007105:Immune Complex Diseases / Q000150:complications* / Q000473:pathology; D007674:Kidney Diseases / Q000150:complications* / Q000276:immunology / Q000473:pathology; D008565:Membrane Proteins / Q000235:genetics
D027321:Anion Transport Proteins; C412733:CLCNKB protein, human; D018118:Chloride Channels; D008565:Membrane Proteins; D015922:Complement C1q