A case of atelosteogenesis type III with bladder stone and proteinuria

抄録

Atelosteogenesis is a chondrodysplasia characterized by severe short-limbed dwarfism with multi-joint dislocation and specific facial features caused by mutations in the gene encoding filamin B. We report a case of atelosteogenesis type III with a large bladder stone and proteinuria. He had hematuria at age 3 years, which was found to be due to kidney stones and hypercalciuria. Hypercalciuria was thought to be due to excessive intake of protein and sodium in addition to immobilization from the original disease. Kidney stones formed, moved to the bladder after the patient became able to sit up. The bladder stone became enlarged due to urinary tract infection. Proteinuria was also detected, which gradually worsened with a glomerular pattern. Surgical removal of the bladder stone and the kidney biopsy were performed concomitantly. The stone consisted of calcium phosphate and magnesium ammonium phosphate. The kidney biopsy showed minor abnormalities. Postural proteinuria was considered to be the cause since he kept sitting position during the day. As he started to move by shuffling, proteinuria decreased. Bladder stone and proteinuria should be born in mind when seeing patients assuming a long-term sitting position.