MANHASSET, N.Y. (CBSNewYork) — In what amounts to a medical first on Long Island, a drug newly approved by the Food and Drug Administration to treat a debilitating neurological disorder is helping two sisters who are gaining more mobility.

As CBS2’s Vanessa Murdock reported, Lisa Panzica, 40, and her sister Laura Chamaidan, 38, have struggled since childhood with a neurological disease that confines them to wheelchairs or motor scooters.

But on Thursday, inside Northwell Health’s main hospital in Manhasset, they praised the physical improvements they have seen in just months after being treated with a new drug called Spinraza.

“I have less fatigue, more stamina. I’m able to move my extremities with less effort,” Panzica said.

Their physician described how the siblings were born with SMA, or spinal muscular atrophy – a chromosomal disorder.

“It’s the most common genetic condition affecting the nervous system in children,” said Dr. Anthony Geraci of neuromuscular medicine at Northwell Health. “It affects one in 6,000 live births.”

Despite the disease, Chamaidan is a mother of three. She tearfully described how SMA limited her interaction with her children.

“The hardest thing about being a mom is not being able to pick them up when they cry, or go on rides with them,” she said.

But after several treatments with Spinraza, she is now able to stand up in her wheelchair briefly.

“I’ve been able to stand longer. Like my daughter said to me last night, like, ‘Wow mom, you’re standing a long time,’” she said.

Geraci said the drug helps to stimulate crucial proteins that strengthen leg muscles. But as is often the case with new drugs, it is quite expensive.

“The treatment is $375,000 a year,” he said.

Fortunately, the sisters’ insurance covers the treatments. But their physician said they are trying to convince more insurers to expand coverage, which right now has mostly been limited to children – all in the hopes that they can one day leave their wheelchairs behind.

The new treatment has been approved for six more Northwell Health patients, and a dozen more are being evaluated for potential treatment.