One family’s journey to an FSGS diagnosis and the simple warning sign they almost missed.
Zane was just 15 months old when his parents noticed something wasn’t right. His eyes, legs and belly were very swollen. At first, it seemed like allergies. As soon as the pediatrician saw Zane, he knew instantly it was not allergies. Urine and blood tests revealed that proteins were not staying within his body where they should.
That led to a diagnosis Zane’s family had never heard of: focal segmental glomerulosclerosis (FSGS), a rare, progressive kidney disease that affects people of all ages — around 40,000 in the United States.1
With no FDA-approved treatments, the road ahead was uncertain. “You never imagine that someone you love will face a serious disease,” said Zane’s mother, Karlene. “The diagnosis hit us like a tidal wave — we were scared, confused, and completely overwhelmed.”
The clue: Protein in the urine
Typically, blood is filtered through the kidneys to remove waste and excess fluid while keeping important substances circulating in the body. This happens in tiny filtering units called glomeruli, where specialized cells called podocytes act like a net, letting waste pass into the urine while holding back larger molecules like protein.
In FSGS, podocytes are damaged, like a net with torn holes, allowing protein to leak into the urine, creating a harmful condition called proteinuria. Lowering proteinuria helps protect the kidneys and slow disease progression, which is especially critical for children, who often experience faster declines in kidney function than adults.2,3
“Proteinuria is one of the clearest signals we have when the kidneys are under threat,” said Jula Inrig, M.D., chief medical officer of Travere Therapeutics. “Reducing proteinuria means protecting kidney function and slowing disease progression, outcomes that make a real difference for people living with FSGS.”
The diagnosis: Understanding FSGS
Early symptoms of FSGS can be subtle and easily misinterpreted. Swelling, fatigue, and weight-gain are often misdiagnosed, while foamy urine — a classic sign of protein in the urine — may appear harmless and not be recognized as an indicator of kidney disease.
A routine urinalysis, sometimes during a school or an annual physical, may be the first clue that proteinuria is present. From there, additional tools like blood tests, a kidney ultrasound and a kidney biopsy can confirm a diagnosis.
In FSGS, rising proteinuria accelerates kidney damage, often leading to kidney failure within 5-10 years.4
Looking to the future
FSGS weighs heavily on patients and families. For adults, it can disrupt careers and relationships. For children like Zane, it can reshape what childhood looks like. Travere Therapeutics is working to change that.
“FSGS has long been managed by a patchwork of medications that often fail to address its root cause,” Dr. Inrig said. “We’re deeply committed to advancing the scientific understanding of FSGS and working with the community toward solutions to preserve kidney health.”
While no approved treatments exist today, research suggests potential therapies may finally be within reach.5 Scientific innovation from Travere and others in the community is helping to accelerate the path to new treatments in rare kidney disease. That’s good news for families like Zane’s.
“FSGS turned our world upside down,” Karlene said. “But now with more attention on FSGS, it gives us strength and hope for what lies ahead.”
Read more stories from people living with FSGS at RKDandMe.com
References
1 Focal segmental glomerulosclerosis. NephCure Kidney International. Accessed August 5, 2025. https://nephcure.org/wp-content/uploads/2021/02/nc.factSheet.FSGS_210106.pdf.
2 Yang EM, Kim J, et al. Longitudinal progression trajectory of estimated glomerular filtration rate in children with chronic kidney disease: results from the KNOW-Ped CKD (KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease). Kidney Res Clin Pract. 2025;44(2):376-388. doi: 10.23876/j.krcp.23.198.
3 Zhu D, Judge PK, et al. Improvements in kidney outcomes over the years: reason for optimism but a challenge for trialists. Am J Kidney Dis. 2024;83(4):427-428. doi: 10.1053/j.ajkd.2023.12.008.
4 Bensink ME, Goldschmidt D, et al. Kidney failure attributed to focal segmental glomerulosclerosis: a USRDS retrospective cohort study of epidemiology, treatment modalities, and economic burden. Kidney Med. 2023;6(2):100760. doi: 10.1016/j.xkme.2023.100760.
5 Rheault MN, Alpers CE, Barratt J, et al. Sparsentan versus irbesartan in focal segmental glomerulosclerosis. N Engl J Med. 2023;389(26):2436-2445. doi: 10.1056/NEJMoa2308550.
