Cambridge-based Sarepta Therapeutics said Tuesday that a patient died while taking its closely watched gene therapy for muscular dystrophy, sending company shares plummeting in morning trading.

The young man died of acute liver injury, a known side effect, Sarepta said in a statement. But the company said the “severity” of the patient’s case had not previously been seen with the therapy, called Elevidys. It’s the first known patient death with the therapy, which has been used in more than 800 patients, the company said.

In 2023, Elevidys received expedited U.S. approval despite concerns from some Food and Drug Administration scientists about its effectiveness in treating Duchenne muscular dystrophy.

Shares of the Cambridge, Massachusetts-based company fell more than 26% to about $74 in Tuesday trading.

Elevidys uses a disabled virus to insert a replacement gene for producing dystrophin into patient cells. It costs $3.2 million for a one-time treatment.

Google has struck a deal to buy cybersecurity firm Wiz for $32 billion in what would be the tech giant’s biggest-ever acquisition at the same time it’s facing a potential breakup of its internet empire.

The proposed takeover announced is part of Google’s aggressive expansion into cloud computing during an artificial intelligence boom. The frenzy is driving demand for data centers and intensifying competition between Google and two other tech powerhouses, Microsoft and Amazon.

If the all-cash transaction is approved by regulators, Wiz will join Google Cloud — an increasingly important part of its business separate from the search and advertising operations that account for most of the $350 billion annual revenue at Google’s parent company, Alphabet.