Ozzy Osbourne, lead singer of Black Sabbath, has died at age 76. He said he had been previously diagnosed with a form of Parkinson’s disease linked to the gene PRKN 

On July 22 Ozzy Osbourne, lead singer of Black Sabbath, died at age 76. The “Prince of Darkness” had been outspoken about keeping up with stage performances and touring while undergoing care for a form of Parkinson’s disease linked to the gene PRKN, which makes a protein called parkin. He played his last live performance with his bandmates in Birmingham, England, on July 5.

“It’s been terribly challenging for us all,” Osbourne said in a 2020 Good Morning America interview in which he discussed his diagnosis.

“There’s so many different types of Parkinson’s,” said Sharon Osbourne, Ozzy Osbourne’s wife, during the interview. “It’s not a death sentence by any stretch of the imagination, but it does affect certain nerves in your body.”

Ozzy Osbourne’s cause of death was not disclosed. The late heavy metal musician had often openly shared his intense lifestyle and experience with drug use, which may have worsened the progression of his form of Parkinson’s, according to the New York Times.

Parkinson’s disease is a neurodegenerative condition in which nerve cells, largely in the basal ganglia of the brain, deteriorate or die. According to the National Institute on Aging, the illness typically progresses with age (most people develop the disease after age 60), and it is known for causing tremors, stiff muscles, balance issues, slowed movement and other mobility problems. People may also experience difficulty swallowing, chewing and speaking, as well as mental health issues, including depression and mood changes. Emerging research suggests that acting out dreams might also predict Parkinson’s disease.

PRKN is one of the genes implicated in Parkinson’s disease. It is involved in maintaining mitochondrial function, which could affect cellular energy—but how that exactly leads to disease is unclear, according to MedlinePlus. Parkinson’s disease has been linked to more than 200 mutations in this gene, some of which may cause issues with protein production, durability and function.

In the 2020 Good Morning America interview, the Osbourne family disclosed Ozzy Osbourne’s condition. He had volunteered to have his genome sequenced in 2010 to see if his DNA could offer more clues about his health.

Does Parkinson’s Disease Cause Death?

Data on Parkinson’s disease and mortality are inconsistent. Some studies suggest that those with the condition, particularly an advanced or severe form, have a death rate that is about 1.5 times higher than that of the general population, according to the American Parkinson Disease Association. Parkinson’s disease, in combination with another disease or injury, such as a fall, an ulcer or pneumonia, could also increase the likelihood of death.

While incurable, Parkinson’s is considered a livable disease. Drugs that act on certain brain neurotransmitters, including dopamine—a hormone involved in movement—can help alleviate symptoms. Research on deep-brain stimulation, which was approved for Parkinson’s tremor by the U.S. Food and Drug Administration in 1997, has shown the technology to be an effective treatment.