Bladder dysfunction in Wolfram syndrome is highly prevalent and progresses to megacystis

AIM: Wolfram syndrome is a rare genetic defect in WFS1 or WSF2(CISD2). It includes diabetes mellitus and insipidis, sensorineural deafness, optic atrophy, but not bladder dysfunction. However, this has appeared a common finding in our national referral clinic, and we sought to quantify this problem.

METHODS: Data were collected from a multidisciplinary team managing all Wolfram patients in the UK. The following was analyzed: age, date of non-invasive urodynamics (NIU), symptoms, bladder capacity, voided volume, post-void residual and uroflow pattern. Bladder capacity was given as percentage predicted bladder capacity (PBC). Bladders were divided into normal, overactive (OAB), and underactive (UAB). Symptoms, bladder behavior, and genotyping were correlated. Data were expressed as median (interquartile range).

MAIN RESULTS: Forty patients with Wolfram syndrome were identified, and 38 underwent NIU. This showed normal bladder function (n=4), OAB (n=9), UAB (n=25). Symptoms were present in only 11 children. The different patterns of bladder behavior (OAB vs. normal vs. UAB) were significantly associated with different %PBC (36 (29-59)% vs. 105 (93-233)% vs. 100 (77.5-337)%; p<0.001), and percentage emptying (100 (80-100)% vs. 100 (87-100)% vs. 69 (48-93)%; p<0.05). There was no association of genotype, symptoms and bladder behavior. Patients with megacystis were older: [13.4 (9.7-16.1) vs. 15.4 (13.9-18.7) years; p<0.05).

CONCLUSION: Bladder dysfunction is very common in Wolfram syndrome (~90%), but most children cope (symptoms ~30%). With time there is a significant progression to megacystis, which may represent an underlying neuropathic myogenic failure and is likely to require intervention in the future.

LEVEL OF EVIDENCE: Level II (National cohort study of prognosis).