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.