Medullary sponge kidney associated with primary distal renal tubular acidosis and mutations of the H+-ATPase genes.

BACKGROUND: Medullary sponge kidney (MSK) is a rare congenital disease characterized by diffuse ectasia or dilation of precalyceal collecting tubules. Although its pathogenesis is unknown, the association with various congenital diseases suggests that it could be a developmental disorder. In addition to the typical clinical features of nephrocalcinosis and urolithiasis, patients with MSK show tubular function defects of acidification and concentration. These are considered to be secondary to morphological changes of collecting tubules. Primary distal renal tubular acidosis (dRTA) is a rare genetic disease caused by mutations in different genes involved in the secretion of H(+) ions in the intercalated cells of the collecting duct required for final excretion of fixed acids. Both autosomal dominant and autosomal recessive forms have been described, the latter is also associated with sensorineural hearing loss. METHODS AND RESULTS: We report two patients presenting with dRTA, late sensorineural hearing loss and MSK, in whom molecular investigations demonstrated the presence of mutations of the H(+) proton pump ATP6V1B1 and ATP6V0A4 genes. CONCLUSIONS: These observations, including a previous description of a similar case in the literature, indicate that MSK could be a consequence of the proton pump defect, thus can potentially provide new insights into the pathogenesis of MSK.

Medullary sponge kidney associated with multivessel fibromuscular dysplasia: report of a case with renovascular hypertension.

Medullary sponge kidney (MSK) is a congenital anomaly characterized by dilatation of the collecting ducts of Bellini associated with defective urinary acidification and concentration. Medullary nephrocalcinosis/ nephrolithiasis is the usual presentation in adults, however neonatal and childhood cases are being reported with increasing frequency. Among the conditions associated with MSK are Beckwith-Wiedemann syndrome/hemihyperplasia (13%), horseshoe kidney, congenital small kidney, hyperparathyroidism, Caroli syndrome, congenital hepatic fibrosis, Ehlers-Danlos syndrome, Marfan syndrome, immotile cilia syndrome, and arterial fibromuscular dysplasia. This article describes an adult female who underwent nephrectomy for renovascular hypertension due to multivessel fibromuscular dysplasia with small left kidney found to be associated with MSK.

Rim esponja medular / Medullary sponge kidney

Rim esponja medular (REM) é uma anormalidade congênita, rara, da medula renal caracterizada por dilatações e malformações císticas dos túbulos coletores. REM é assintomático, de curso benigno, na fase inicial, e o diagnóstico essencialmente radiológico. em fases tardias, tem alta morbidade quando complicado com cálculos ou infecção, que acabam clinicamente por gerar cólicas renais de repetição, hematúria ou mesmo pielonefrite crônica. Não há relato na literatura médica brasileira sobre REM. Apresentamos dois casos diagnosticados na Clínica de Nefrologia do Hospital do Servidor Público Municipal - HSPM - São Paulo, salientando as manifestações radiológicas na ausência de complicações, uma vez que os casos publicados na literatura médica mundial sempre se apresentaram associados à litíase ou outra condição patológica formadora de cálculos.

Medullary sponge kidney (REM) is a congenital abnormality, rare, renal medulla and malformations characterized by cystic dilatation of collecting tubules. REM is asymptomatic, a benign course, in the initial phase, and essentially radiological diagnosis. in late stages, when they have high morbidity or infection complicated calculations, you end up generating clinically recurrent renal colic, haematuria or chronic pyelonephritis. There is no report in the Brazilian medical literature about REM. We present two cases diagnosed in the Clinic of Nephrology, Hospital do Servidor Publico Municipal - HSPM - São Paulo, highlighting the radiographic manifestations in the absence of complications, since the cases published in medical literature had always been associated with gallstones or other pathological condition forming calculations.