Rare Disease Education: Renal Coloboma Syndrome
Editor: Kelsey LaFayette, DNP, RN, FNP-C
"When you hear hoofbeats, think of horses, not zebras,” is a common saying in medical education that means you should think of common conditions first, instead of rare ones, in making a diagnosis. “Rare” is a relative term though and about 7,000 rare, or "zebra," conditions affect more than 350 million individuals worldwide. Although these conditions collectively affect an enormous number of people, each of these conditions individually is rare enough that it can be difficult to secure the resources to study them and to develop treatments and cures. Likewise, awareness of rare conditions may be low and health care professionals may not be familiar with their signs and symptoms making it more difficult to reach a correct diagnosis and provide effective treatments.
To increase knowledge about rare conditions, Osmosis and the National Organization for Rare Diseases (NORD) have collaborated on an initiative to bring education and awareness to the public. We are excited to be a part of this initiative because we believe everyone deserves quality health care, no matter how rare their condition.
Zebra of the Week: Renal Coloboma Syndrome
Welcome to the first Zebra Newsletter of 2025! The Year of the Zebra team thanks you for a 2024 beyond expectations. With over 134 million impressions across platforms, Year of the Zebra content is fulfilling its goal of spreading awareness on rare diseases and educating individuals far and wide. We continue to stand with the rare disease community and are excited to continue the movement into this new year 2025. Get ready for a whole new set of Zebra conditions!
Renal coloboma syndrome, also known as papillorenal syndrome, is a genetic condition that is excessively rare. With only just over 60 cases ever described, it is so rare that there are no formal criteria to establish the diagnosis. It is inherited in an autosomal dominant pattern, meaning only one copy of a mutated gene is needed to cause the condition. Most cases are caused by mutations in a gene called PAX2 which is involved in the development of the kidneys and eyes.
Renal coloboma syndrome is characterized by abnormalities in the kidneys and in the eyes. The kidneys tend to be small and underdeveloped. Kidney function is impaired and often results in kidney failure by early adulthood. In the eyes, the most common manifestation is a coloboma of the optic disc, a birth defect where the optic disc, or the point where the optic nerve exits the eye, appears larger and hollowed because it didn’t develop as usual. This can manifest as vision loss or blind spots.
To learn more about the diagnosis and treatment of renal coloboma syndrome, watch the dedicated Osmosis video on YouTube and Osmosis.org.
Meet Gillian
Gillian was shocked after being diagnosed with end-stage kidney failure in her 20s. Regardless of the cause, this upends life as she knew it. She has been getting hemodialysis three times a week for 20 years now, with each session lasting 4.5 hours. Hear Gillian tell her story as she discusses the pressures of dialysis, including how difficult it was to get her head around the dietary and fluid restrictions. Nobody struggles alone and there are plenty of people here for support.
