Unusual renal features of Lowe syndrome in a mildly affected boy

The oculocerebrorenal syndrome of Lowe (OCRL) is an X-linked disorder chara cterized by congenital cataracts, mental retardation, and renal tubular dys function, The gene responsible for OCRL was identified by positional clonin g and encodes a lipid phosphatase, phosphatidylinositol 4,5, bisphosphate [ PtdIns(4,5)P2]5-phosphatase, which localizes to the Gels apparatus and is s uspected to play a role in Golgi vesicular transport [Suchy et al,, 1995], In addition to the ocular and renal manifestations, most boys with OCRL hav e cognitive problems and maladaptive behaviors including tantrums and stere otypies, We report a boy with a history of congenital cataracts and mild de velopmental delay who was also found to have hematuria with proteinuria but minimal signs of renal tubular dysfunction, Subsequent renal biopsy was co mpatible with a diagnosis of a noncomplement fixating chronic glomeruloneph ritis, Despite the atypical renal findings, skin fibroblast analysis for Pt dIns (4,5)P2 5-phosphatase was performed, and enzyme activity was low, cons istent with the diagnosis of OCRL, Western blot analysis from cell lysates showed the ocrl protein was decreased in size and amount. Our report shows atypical renal features of OCRL in a mildly affected boy, The possibility o f OCRL should be considered in boys: with cataracts and glomerular disease, even in the absence of renal tubular defects and frank mental retardation usually associated with the syndrome, Published Wiley-Liss, Inc.'.