Hypercalciuria and ultrasound abnormalities in children with cystinosis.

We noted microscopic haematuria in children with cystinosis. To investigate this we studied urinary calcium excretion and undertook renal ultrasound scans. Most patients had elevated urinary calcium excretion and all had abnormal appearances on ultrasound scan, ranging from increased cortical echogenicity only to those with increased cortical and medullary echogenicity. The ultrasound scan appearance was graded and correlated with laboratory parameters. It remains unclear as to the aetiology of the ultrasound findings and whether they are a consequence of treatment or a hitherto unrecognised feature of the disease.