Bilateral aniridia and congenital ureteral valve: Role of genetic testing

Mol Genet Genomic Med. 2020 Apr;8(4):e1183. doi: 10.1002/mgg3.1183. Epub 2020 Feb 14.

Abstract

Background: Congenital aniridia involves total or partial hypoplasia of the iris and is due to a deficiency in PAX6 gene expression. WAGR syndrome is comprised of Wilms tumor, aniridia, genitourinary abnormalities, and intellectual disability. Numerous genitourinary pathologies may be associated with WAGR syndrome, necessitating an evaluation of the genitourinary anatomy. The WT1 is vital for the development of kidneys, ovaries in females, and testes in males. WT1 gene mutations result in a WT1 protein with a decreased ability to bind to DNA, leading to uncontrolled growth, and cell division in the kidney which permits the development of Wilms tumor. A congenital ureteral valve is an exceedingly rare cause of obstructive uropathy.

Results: A renal and bladder ultrasound demonstrated a renal cyst. A voiding cystourethrogram revealed grade 3 vesicoureteral reflux, and a MAG3 renal scan showed ureteropelvic junction obstruction and hydronephrosis. A ureteral stent was inserted at 3 months of age after which the renal cyst resolved. The patient was urinary tract infection-free at 27 months of age. Genetic testing confirmed a heterozygous alteration in PAX6 (c.495delG, p.Thr166Leufs*41) and no abnormalities of WT1, excluding WAGR syndrome.

Conclusion: The genitourinary risks potentially associated with aniridia necessitate prompt genetic analysis to evaluate for WAGR syndrome.

Keywords: aniridia; genetics; pediatric urology; ureteral valve; wilms tumor.

Publication types

  • Case Reports

MeSH terms

  • Aniridia / genetics*
  • Aniridia / pathology
  • Child, Preschool
  • Diagnosis, Differential
  • Female
  • Genetic Testing*
  • Humans
  • Kidney / diagnostic imaging
  • Mutation
  • PAX6 Transcription Factor / genetics*
  • Syndrome
  • Urethra / abnormalities
  • Urethra / diagnostic imaging
  • Urethral Obstruction / genetics*
  • Urethral Obstruction / pathology

Substances

  • PAX6 Transcription Factor
  • PAX6 protein, human