Two Boys With Rare Genetic Disorder Find Hope in New FDA-Approved Drug

Dr. Rachel Mendez MD, Medical Science Writer

✨ Why this is good news

Hunter syndrome is a rare genetic disorder where the body cannot break down certain sugars, causing damage to organs and the brain.

First brain-penetrating treatment.Before this FDA-approved drug, no treatment could reach the brain to slow cognitive decline in severe Hunter syndrome. Now boys like JT and his friend have a chance to preserve their development and thinking abilities.
Two boys treated together.JT and his friend were diagnosed the same week in March, and both became among the first children to receive the new therapy. This shared experience gave their families mutual support and hope instead of facing the disease alone.
Slows devastating brain damage.Hunter syndrome causes sugars to build up in brain cells, leading to severe developmental delays and early death. The new drug targets the brain directly, offering a real chance to slow or stop that damage for the first time.
FDA approval opens access.Because the treatment is now FDA-approved, more children with Hunter syndrome across the country can receive it, not just those in clinical trials. This means families no longer have to wait or hope for experimental options that may never come.

Two families in Greenville, South Carolina received the same rare diagnosis for their sons during the same week in March. Now their boys are among the first children to receive a newly approved treatment that offers a chance at slowing a devastating brain disease.

Both boys were diagnosed with Hunter syndrome, also known as MPS II, a genetic disorder that prevents the body from producing a crucial enzyme needed to break down complex sugars. Without that enzyme, sugars build up in cells and damage organs. In severe cases, the condition affects the brain and leads to developmental delays. JT, one of the boys, has neuronopathic Hunter syndrome, a more severe early onset type that affects the brain.

The same week both families learned their sons had the disorder, the U.S. Food and Drug Administration approved a new drug called Avlayah. Laura Buch, a physician assistant with the Greenwood Genetic Center, explained that previous treatments could replace the missing enzyme but could not cross the blood-brain barrier, the protective boundary that blocks many medications from reaching the brain. The new drug uses what Buch described as an enzyme transport vehicle to carry the enzyme past that barrier and into the central nervous system.

Early results have been encouraging. Buch said patients treated with Avlayah showed behavioral improvement and neuropsychological outcomes that improved over time. The two boys now receive their infusions together at the Prisma Health infusion center, where the hospital schedules both families on the same day because of the bond they have formed.

For families facing a disease this rare, finding someone who understands the experience firsthand has made a significant difference. “This specific journey is just something that’s hard to understand,” said Marie Laiewski, mother of James. “It’s very special to have another family who understands the exact struggles.”

Hannah Burgess, mother of JT, echoed the sentiment. “We know that these boys will be walking this path for life together and we truly hope that they can lean on one another, know that they are not alone,” she said.

Avlayah is not a cure for Hunter syndrome. Buch said clinical trials are currently underway exploring gene therapy as a potential path toward a cure. For now, the families hold onto the progress already made. “This treatment is important to us,” Laiewski said. “Now there is hope.”

This article is for informational purposes only and does not constitute medical advice. The information presented is based on published research and official announcements. Always consult a qualified healthcare professional before making any medical decisions.