Cortical nephrocalcinosis in an infant caused by primary hyperoxaluria type 1

Abstract

An 8-month-old boy was referred for an upper gastrointestinal study for vomiting. Scout abdominal radiograph shows bilateral cortical nephrocalcinosis (Fig. 1, arrows). US shows hyperechoic cortical rim with acoustic shadowing confirming cortical nephrocalcinosis (Fig. 2, arrows). Laboratory and genetic testing confirmed primary hyperoxaluria type 1 (PH-1). PH-1 is a rare autosomal-recessive disorder resulting from deficiency of the hepatic peroxisomal enzyme alanineglyoxylate aminotransferase, which causes excessive oxalate formation and calcium oxalate deposition in various organs. Kidneys show cortical or medullary nephrocalcinosis and recurrent urolithiasis causing progressive renal failure [1]. Skeletal manifestations of PH-1 sometimes result from oxalate deposition but more commonly result from chronic renal failure, leading to secondary hyperparathyroidism and renal osteodystrophy [2]. Findings include metaphyseal sclerotic lines and bands, lucent bands, cystic changes, permeative lucencies and vertebral diffuse or endplate osteosclerosis (rugger jersey appearance). Flat pelvic bones, carpal and tarsal bones, and patella might show a radiolucent rim.