Affected individuals have severe urinary bladder voiding dysfunction. The external urinary sphincter fails to relax resulting in increased bladder pressure which can result in vesico-ureteric reflux, dilated ureters and hydronephrosis. Affected individuals may be identified prenatally due to an enlarged bladder or with recurrent urinary tract infections, incontinence or renal impairment.
Affected individuals may also have significant bowel voiding problems resulting in constipation.
A characteristic grimace is present on attempts to smile.