"At present, we can do the diagnostics and confirm for the patient that this is the disease they have, but we cannot offer any treatment," says Friedhelm Hildebrandt, M.D., the U-M's Frederick G.L. Huetwell Professor for the Cure and Prevention of Birth Defects. "Our only hope is to work out the mechanism to understand where it comes from. Now that we have the gene, at least we know where to start asking questions."
Working with an international team of scientists, Hildebrandt and Edgar A. Otto, Ph.D., a U-M research investigator, found that children who inherit, from both parents, mutated forms of a gene called inversin develop nephronophthisis* type 2, which causes renal failure in infancy. Results from the U-M study were published in the August, 2003 issue of Nature Genetics.
"We found nine distinct recessive mutations in the inversin gene in nine infants with early-onset NPHP from seven different families," Otto says. "We found no inversin mutations in 100 healthy control subjects."
Finding the gene responsible for NPHP2 is especially important, not only because it could lead to a future treatment, but also because of intriguing links between NPHP2 and a life-threatening genetic disorder called polycystic kidney disease or PKD, which affects 500,000 people, mostly adults, in the United States.
"Like polycystic kidney disease, NPHP2 is characterized by extensive kidney scarring," Hildebrandt explains. "Infants with NPHP2 also develop enlarged kidn
Contact: Sally Pobojewski
University of Michigan Health System