A study of families with an inherited kidney disorder shows how a mutation affects a protein produced in urine.
Researchers at Wake Forest University have been investigating a family from Western North Carolina who have been plagued with a rare kidney disease, called familial juvenile hyperuricemic nephropathy. They now find that affected members have a mutation in a gene that produces a protein called uromodulin, which is found in urine.

The function of uromodulin was not known, but this research suggests it acts like a kind of 'glue' in the kidney tubes, helping in the re-absorption of water and salts and preventing leaking from the tubes. The mutation impairs this function. A related genetic kidney disease, called medullary cystic kidney disease, appeared to be linked to the same mutation once other families were brought into the study.

It may now be possible to gain a deeper understanding of these two kidney diseases. For instance, it will be possible to offer gene testing to discover whether people in an affected family carry this mutation. It will also be helpful to do this gene test on kidneys intended for donation.