An X-linked recessive inheritance pattern, in which only males are affected, and the mother is an asymptomatic carrier, should raise the possibility of Lowe syndrome (mutation in the OCRL-1 gene); Dent disease, type 1 (mutation in the CLCN5 gene); and Dent disease, type 2 (mutation in the OCRL-1 gene) [27–29]. The gene discussed is CLCN5; the disease is Dent disease.