Dent's disease is proximal tubulopathy characterized with low molecular weight proteinuria (LMWP), hypercalciuria, nephrocalcinosis and sometimes, progression to chronic renal failure. Oculocerebrorenal (Lowe) syndrome is an X linked multisystem disease characterized by renal Fancony syndrome, mental retardation and congenital cataracts. Our first patient is 12 year-old boy who was found to have LMWP, hypercalciuria, mild hyperaminoaciduria and intermittent microscopic hematuria. He fulfilled diagnostic criteria for Dent's disease, but lacked mutation in CLCN5. Sequencing of candidate genes revealed a mutation in his OCRL1 gene (Hoopes et al 2005), which encodes for enzyme PIP2 5-phosphatase. By Western blot analysis the enzyme was not detected, and decrease d activity of the enzyme PIP2 5-phosphatase was observed, in cultured skin fibroblasts from him. The boy had only mild mental retardation but no neurological deficit or congenital cataracts, which are typical for Lowe syndrome. The second patient is 10 year-old boy who presented with LMWP and hypercalciuria. He was also found to have mutation in OCRL1 gene (Utsch et al in press). He had normal intelligence, neurological status and lack of cataracts. Among nine patients with Dent's disease and OCRL1 mutations two come from Macedonia. These patients represent a new entity termed Dent 2 disease. Our original observation of elevated muscle enzymes and CPK in the first patient was extended to other Dent/Dent 2 patients (Utsch et al, in press). In conclusion, children with Dent phenotype who lack CLCN5 mutation should be tested for OCRL1 mutations which are not necessarily associated with congenital cataracts.