New Screening Criteria Needed for Polycystic Kidney Disease
Updated ultrasound guidelines may be useful in clinics where genotyping is seldom performed
FRIDAY, Oct. 24 (HealthDay News) -- New ultrasound screening criteria are needed in the diagnosis of polycystic kidney disease because current criteria may miss some patients with a milder form of the disease caused by mutations in the PKD2 gene, according to study findings released online Oct. 22 in the Journal of the American Society of Nephrology.
York Pei, M.D., of the University of Toronto in Ontario, Canada, and colleagues assessed 577 subjects from 58 PKD1 families and 371 subjects from 39 PKD2 families with renal ultrasound and molecular genotyping. The researchers compared various diagnostic criteria using sensitivity data derived from genetically affected subjects and specificity data from genetically unaffected subjects.
The investigators found that current diagnostic criteria are suboptimal for diagnosing disease in subjects with PKD2 mutations, so they developed new criteria to accurately detect disease in subjects with either PKD1 or PKD2 mutations. Among families of unknown gene type, the researchers determined that disease could be accurately diagnosed by the presence of three or more kidney cysts in subjects aged 15 to 39, two or more cysts in each kidney in subjects aged 40 to 59, and four or more cysts in each kidney in subjects over age 60. They also determined that disease could be excluded in at-risk subjects aged 40 or older with fewer than two kidney cysts.
"These unified diagnostic criteria will be useful for testing individuals who are at risk for autosomal dominant polycystic kidney disease in the usual clinical setting in which molecular genotyping is seldom performed," the authors conclude.