Evaluation of the ISL1 gene in the pathogenesis of bladder exstrophy in a Swedish cohort.

A gene previously linked to birth defects of the bladder does not seem to cause the abnormality in affected patients from Sweden. A research group led by Agneta Nordenskjold from the Karolinska Institutet in Stockholm screened 125 Swedish patients with bladder exstrophy for variants in the ISL1 gene. Recent studies showed association to a SNP near this gene conferring susceptibility to this rare bladder defect, with a protruding bladder outside the belly in new-borns. Nordenskjold’s team found no disease-causing variants in this gene in their patients. The researchers also measured ISL1 activity in embryonic and fetal bladders, and saw expression levels spike at around eight weeks of gestation. This suggests that ISL1 is important for normal bladder development, even if mutations in the gene rarely explain cases of bladder exstrophy in Sweden.