vesicoureteral reflux screening in siblings of patients with known reflux

the prevalence of vesicoureteral reflux (vur) among siblings of children with vur has been reported to be from 4.7% to 51%. the incidence of vur in the general population is less than 1% but it is high in risk groups. in a prospective study we started identifying the incidence and severity of vur and renal parenchymal lesions in the siblings of patients known to have urinary tract infection (uti) with reflux. between october 1994 and february 2002, 31 siblings of 26 index patients were screened with direct voiding cystography. technetium -99m dimercaptosuccinic acid (dmsa) nuclear renal scans were performed in siblings with vur to detect renal scarring. the cystograms were interpreted as showing the presence or absence of vur and the dmsa scan as symmetrical or asymmetrical differential function, with or without renal scar. sixteen of 31 siblings were found to have vesicoureteral reflux representing an incidence of 51.61%. mean age at presentation of the 8 boys and 23 girls was 2.5 years (range 6 months to 12 years). the majority of them were asymptomatic. reflux was unilateral in 11 siblings and bilateral in 5. of 16 siblings with reflux, 6 (37.5%) had a history of symptomatic uti. the frequency of vur was equal in siblings over 6 years and those younger. fifteen of the 16 siblings with vur had dmsa scintigraphy, of whom 5 were normal and 10 (66.66%) showed abnormalities (nine asymmetrical differential function and one parenchymal defect), which was bilateral in 7 and unilateral in 3. this study confirms a significant overall incidence of vur in the siblings of patients with known reflux. the prevalence of reflux in older siblings is similar to those in the younger ones. the high rate of reflux in this population, especially girls, over 6 year old might be attributed to bladder dysfunction.