A five-month-old boy facing immobility or even death because of a rare genetic disorder may get a new lease of life after his parents successfully raised the $3 million needed for a drug to treat his condition.

Baby Zayn - who was diagnosed with Type 1 spinal muscular atrophy (SMA) at about five weeks old - will be able to get the drug Zolgensma by early December, said his parents, Mr Nabeel Salim Abdat and Ms Syahirah Yakub.

"It's like a huge weight off our shoulders," said Mr Nabeel, a 30-year-old data centre engineer, on Friday (Nov 11).

SMA is a neuromuscular disorder that causes muscles to weaken and can lead to declining motor functions, as well as issues such as respiratory problems, scoliosis and osteoporosis.

Zolgensma is a one-time gene therapy that is infused into a baby's veins to stop the condition's progress.

Available in Singapore only via the Special Access Route - which allows for unregistered life-saving drugs to be imported into the country - it is often touted as the most expensive drug in the world, costing almost $3 million.

To raise the needed funds, Mr Nabeel and Ms Syahirah, 31, started a campaign on crowdfunding platform Ray of Hope in mid-August.

With influencers and celebrities raising awareness of it on social media, the campaign garnered almost half the amount needed within a month.

But the fund raising soon plateaued, remaining just shy of $1.5 million for almost two months.

"We were wondering what else we could do. We were running out of ideas," Mr Nabeel said.

In an update on Nov 4, however, Ray of Hope said "several large anonymous donations" had allowed the campaign to raise $3,015,167.50, ahead of its targeted closing date at the end of November.

Mr Nabeel and Ms Syahirah said they did not know who made the contributions that allowed them to hit their target.

But the challenges will not end once Zayn receives Zolgensma.

The infant remains at the National University Hospital, although he has been moved from the paediatric intensive care unit to the high-dependency unit. He continues to depend on tubes for breathing and feeding.

He may also have to continue taking Risdiplam, an oral medication taken daily. Each bottle costs more than $15,000 and lasts him 64 days.

He might also have to take steroids, used to treat liver failure, a known possible side effect of Zolgensma.

In August, its manufacturer, Novartis, reported that a child in Russia and another in Kazakhstan had died earlier this year from acute liver failure about five weeks after taking Zolgensma.

Zayn's parents said they will monitor how their son responds to the drug before deciding on the next step.

Ms Syahirah, a former civil servant, said she has left her job to look after Zayn.

The couple said they are grateful for all the support, both financial and otherwise, that they have received.

"We are very touched by the response and the continued support from the community, from our families and from everyone," Mr Nabeel said.

This article was first published in The Straits Times. Permission required for reproduction.