Medullary sponge kidney associated with distal renal tubular acidosis in a 5-year-old girl

Abstract

Metabolic acidosis, hypercalciuria, hypocitraturia, tubular phosphate reabsorption and growth retardation in the patient improved with alkali therapy.

Bone Disease in Medullary Sponge Kidney and Effect of Potassium Citrate Treatment

“…That overt dRTA causes growth retardation, rickets, hypercalciuria, and nephrocalcinosis as a result of chronic systemic metabolic acidosis is widely known, but the observation that children with idRTA are also shorter than control subjects (11) supports Weger's claim (10) that such an incomplete dRTA may affect bone metabolism. Case reports involving children have described an association among MSK, growth retardation, and overt or incomplete dRTA (12,13). Incomplete dRTA typically causes no overt systemic acidosis but may cause recurrent positive acid loads in periods of increased protein intake or catabolic stress triggering alkali release from the bone and thus leading to a greater bone reabsorption (14); in fact, increased osteoblast and osteoclast activation has been described in idRTA (15), and the G proteincoupled proton sensor OGR1 was recently found to work as a H ϩ -sensing receptor in osteoblasts (16).…”

Identification of GDNF Gene Sequence Variations in Patients with Medullary Sponge Kidney Disease

“…It is believed that it is a congenital disorder with late expression (1,2). MSK prevalence in the general population is uncertain, possibly 5 cases per 10,000 to 100,000 population.…”

A Rare Case of Congenital Distal Renal Tubular Acidosis Combined with Medullary Sponge Kidney

“…But in our patients, three of the pelvic-abdominal ultrasound results showed renal pyramids, which was consistent with a hyperechogenic, radically arranged, no cysts echo display; this is the basis for the diagnosis of MSK. Although it is thought that IVU is the gold standard for diagnosis [1,5], bilateral medullary hyperechogenicity at ultrasound was the first sign that alerted our pediatrician to the presence of MSK. In addition, excretory magnetic resonance urography can visualize small or subtle anomalies in the nondilated urinary tract, such as fine tubular ectasia in MSK [6].…”

“…The characteristic IVU finding of MSK is linear striations and accumulation of contrast in small cysts within the papillae that give a ‘brush-like' or ‘bouquet of flowers' appearance to the renal papillae [1,5]. Because of the risk of contrast agents and radiation, young infants are unsuitable for IVU.…”