Lrig2 is required for maturation of peripheral nerves in the urinary bladder

Leucine-rich-repeats and immunoglobulin-like-domains (LRIG2) variants can occur in urofacial syndrome (UFS), an inherited disease characterised by functional bladder outlet obstruction. We aimed to define the pathobiology underlying UFS which we hypothesised would illuminate how the bladder becomes innervated. Lrig2 was detected in pelvic ganglia supplying autonomic neurons to the bladder, and in neurites and glia emanating from explanted ganglia. One week old Lrig2 mutant mice displayed abnormally patterned bladder nerves, as did mice with mutations of Hpse2, also mutated in some UFS patients. From two weeks postnatally, Lrig2 mutants had urination defects resembling UFS. Molecules implicated in neural biology, including Nos1 which relaxes the bladder outlet, were dysregulated in newborn Lrig2 mutant bladders. These molecular aberrations preceded manifest urination defects. We discovered novel homozygous missense LRIG2 variants in non-syndromic bladder outlet obstruction. Molecules mutated in UFS are required for bladder innervation and LRIG2 variants can occur in non-syndromic bladder disease as well as in UFS.