Mila is a six-year-old orangutan born at the Indianapolis Zoo. Credit: Fred Cate, Indianapolis Zoo
Key points:
- Researchers have diagnosed a 6-year-old orangutan with a rare autosomal recessive disorder.
- It is the first time the disorder has been diagnosed in a primate other than a human.
- The diagnosis gives zoo veterinarians a better idea of what they are dealing with, and lessens the tests Mila must undergo to ensure her health.
Researchers have diagnosed a Sumatran Orangutan at the Indianapolis Zoo with a rare genetic disease, called alkaptonuria. This is the first time the disease has been confirmed molecularly in a primate other than a human. The six-year-old orangutan, named Mila, was born at the Indianapolis Zoo in 2016. Mila had a history of dark urine that turned brown upon standing since birth, but has never shown other symptoms.
After analyzing Mila’s DNA, researchers from the IU School of Medicine Department of Medical and Molecular Genetics unexpectedly diagnosed the orangutan with alkaptonuria.
“This was an unexpected finding that ended years of questions about this animal,” said Marcus Miller, assistant professor of clinical medical and molecular genetics and principal investigator of the study.
Alkaptonuria is a rare, autosomal recessive disorder caused by deficiency of an enzyme called homogentisate 1,2-dioxygenase. As an infant, the only symptom is urine that turns black upon standing. Symptoms typically progress slowly, but can lead to chronic joint pain and decreased mobility later in life.
There have been several reports of the disease in non-human primates, but never any long-term studies, so it is unclear how the disease will impact Mila over time. However, having this diagnosis gives veterinarians a leg up to help Mila as time progresses.
“I think the best part about these results is we can de-escalate some of the other studies that might have been recommended,” said Theodore Wilson, assistant professor of clinical medical and molecular genetics. “We don’t need to use anesthesia for imaging, obtain a kidney biopsy or have guests or veterinarians worried. Even though her urine does still turn dark after being out in the environment, fortunately, now it doesn’t need to be a problem that is alarming.”