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A 3-year-old boy is brought to the emergency department by his mother after she noticed an abdominal mass during bath time. They are new immigrants to the country, though the child is up to date on his vaccinations. Physical exam reveals a non-tender abdominal mass near the right kidney and partial absence of one iris. Which of the following drugs is indicated for the treatment of this tumor?
Content Reviewers:Rishi Desai, MD, MPH
WAGR syndrome stands for Wilms’ tumor, aniridia, genitourinary anomalies, and mental retardation, which is now called intellectual disability, and this is a genetic disorder that’s caused when a part of chromosome 11 is missing, or deleted.
Not everyone with WAGR has all of the symptoms, for example only about a half of the individuals have Wilms’ tumor.
The most specific feature of WAGR syndrome is aniridia, which is the complete or partial absence of the iris, the colored part of the eye. And this is an easily noticeable feature, and it’s present at birth, so it’s usually the first thing to raise suspicion of WAGR syndrome.
Now, a normal iris controls how much light enters the eye, and it constricts the pupil when there’s a lot of light around to keep the vision sharp. With aniridia, too much light gets into the eye, which leads to blurry vision and photophobia, which is discomfort when the eyes are exposed to light.
Wilms’ tumor, also called nephroblastoma, is generally a malignant kidney tumor that affects children.
Wilms’ tumor’s composed of metanephric blastema, which is a cell type that’s seen in the developing kidney, stromal cells which are part of the connective tissue, and epithelial cells which self-organize into primitive glomeruli and tubules.
Now, that hypertension is a result of increased renin secretion; which either comes from the tumor itself or from healthy kidney tissue that secretes renin because it’s physically compressed by the tumor.
It’s worth noting that Wilms’ tumor isn’t specific for WAGR syndrome; in fact, it most commonly happens in otherwise-healthy children, and can be a part of other syndromes like Beckwith-Wiedemann syndrome.
Fortunately, Wilms’ tumor is also treatable and has a fairly high cure rate when it’s treated with a combination of chemotherapy, radiation, and nephrectomy, which is removal of the kidney.
The most common genital defect in boys with WAGR syndrome is undescended testes, also called cryptorchidism, as well as hypospadias, where the urethra exits the penis on the underside instead of at the tip.
The most common genital defect in girls is streak ovaries, which are undeveloped and nonfunctional ovaries that are at an increased risk for developing a tumor called gonadoblastoma.
Finally, someone with WAGR syndrome might have ambiguous genitalia, meaning they don’t appear to be either clearly male or clearly female.
Finally, intellectual disability is present in many but not all people with WAGR syndrome, and it’s also associated with conditions like autism or ADHD, all of which are usually recognized in childhood.
- "Robbins Basic Pathology" Elsevier (2017)
- "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
- "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
- "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
- "WAGR Syndrome: A Clinical Review of 54 Cases" Pediatrics (2005)
- "Brain-Derived Neurotrophic Factor and Obesity in the WAGR Syndrome" New England Journal of Medicine (2008)
- "Association of Wilms's Tumor with Aniridia, Hemihypertrophy and Other Congenital Malformations" New England Journal of Medicine (1964)