A new approach to mRNA in proximal tubule cells of patients with CLCN5 channelopathy

ClC-5 is a chloride channel whose gene mutations have been reported to be a ssociated with X-linked nephrolithiasis (XRN), X-linked recessive hypophosp hatemic rickets (XLRH), Dent disease, and idiopathic low-molecular-weight p roteinuria (ILMWP) in Japanese children. To establish more efficient screen ing for CLCN5 abnormalities, we developed a new diagnostic method using rev erse transcription and polymerase chain reaction (RT-PCR) of cultured renal tubular cells from the urine of patients. Using this new method, we succes sfully detected microdeletion of ClC-5 mRNA in a patient and splicing abnor mality of the CLCN5 Cl channel.