A Georgetown family is trying to beat the clock and raise money for research before a rare disease claims a little boy's legs.

Three-year-old Ethan Rosenberg is the only child in Texas diagnosed with the ultra-rare brain disease

Symptoms include developmental delay, microcephaly, seizures, malformation of the brain and low-muscle tone. The few patients that learn to walk independently tend to lose that ability a few months or a few years later.

But an anonymous donor stepped up last month and offered to match donations up to $100,000.

Ethan's parents said he has worked so hard to learn to walk, and they don't want to see him lose that ability.

"For him, I want him to keep all of the skills that he's learned and I want him to keep walking and I hope to see him running one day and climbing a tree and learning words," said Suchan Rosenberg, Ethan's mother.

The Rosenbergs' journey began when little Ethan first missed his 2- and 4-month-old milestones. At 10-months-old, Ethan started having breath-holding spells and turning blue from them. Those resulted in ER visits and eventually an MRI, which showed a brain bleed, among other damage.

The Rosenbergs were told at this point, Ethan needed more aggressive therapy. This led to an autism diagnosis.

On Dec. 23, it will be one year since Ethan was diagnosed with the ultra-rare genetic neurological brain disorder.

He entered full time therapy in October.

"I think he is more aware of his surroundings, he's more curious about his surroundings," said Suchan.

But Ethan could lose his achievements if research doesn't find a cure before SPG47 takes over his little body.

"We don't know if he'll cognitively start to decline but that's a prediction, so our main focus is just to make sure that we can raise awareness and funding so that these doctors can find a treatment to help halt the progression since it is degenerative," Suchan said.

The Rosenberg's focus has sharpened after an anonymous donor last month offered to match every dollar raised up to $100,000.

But there's a catch.

The deadline is Jan. 31.

So it's a race against time for the Rosenbergs.

They hope to raise money fast enough for researchers to find a cure so Ethan can continue walking.

According to CureSPG47.org, the ultimate goal is to raise $4 million so researchers can work on the following projects:

"Dr. Darius Ebrahimi-Fakhari of Boston Children's Hospital is pursuing a drug screening experiment on fibroblasts derived from SPG47 patients. The process begins with obtaining skin cells from the patient and the same gender parent. IPSC stem cells are developed from the tissue, and then differentiated into central motor neuron cells which can be maintained and studied in a lab. The goal of the project is to test whether various compounds which are FDA-approved for other disorders might offer some benefit to the cells affected by SPG47.

Cure SPG47 has engaged Dr. Mimoun Azzouz of the University of Sheffield to develop a gene therapy proof-of-concept. His team will develop a viral vector capable of delivering a good, working copy of the AP4B1 gene to the central motor neurons of a knockout mouse as well as fibroblasts derived from SPG47 patients. If successful, this research will provide the basis for pursuing human clinical trials in the coming years."

To donate, go here.