Why Some People Are Immune To Deadly Diseases Over Others?

For over 15 years, Dr Anthony Shum, a pulmonologist at the University of California, San Francisco has been studying a rare genetic disorder called the COPA Syndrome. It stands for coatomer subunit alpha and is a rare, inherited disorder that affects the lungs, joint, and kidney. The National Organization for Rare Disorder also notes that it is a genetic autoimmune disorder that is caused by mutations in the COPA gene. This disease affects families unpredictably—some individuals with the mutation develop severe lung damage early in life, while others remain completely healthy. Now, Shum’s team has discovered a protective genetic variant that may offer new hope for treatment.

A Breakthrough

Researchers found that some relatives of COPA Syndrome patients stayed healthy despite carrying the same COPA gene mutation that causes the disease. The key difference? These unaffected individuals had a protective version of another gene called HAQ-STING.

When scientists introduced HAQ-STING into diseased lung cells from COPA patients, the cells returned to a balanced state, suggesting that this gene could be used as a therapy.

“We really think HAQ-STING could be a gene therapy tool and a step toward a cure,” said Shum, whose findings were published in the Journal of Experimental Medicine.

Families Who Solved The Mystery

Shum’s journey into COPA Syndrome research began in 2011 when he treated a young woman, Letasha, who had severe lung bleeding. Her mother, Betty Towe, mentioned that Letasha’s sister, Kristina, had suffered from similar symptoms. Over the years, Betty had taken both daughters on a four-hour trip to UCSF for treatment. After tracing their family history, Shum discovered that their distant relatives in Texas and Oakland also had lung problems and arthritis. In 2015, Shum, along with scientists from Baylor College of Medicine and Texas Children’s Hospital identified the COPA gene mutation. They realized that it was the common factor behind the illness. However, only some of the 30 individuals with the mutation actually developed symptoms, leaving a major question unanswered.

The Domino Effect

It was established that it occurs when a mutated COPA gene causes another gene STING to go overdrive. The STING that helps fight infections in COPA patients, remain permanently active, which leads to chronic inflammation that damages the lungs, kidneys, and joints. In 2020, while studying STING’s role in the disease, researchers discovered a key variation: HAQ-STING. This version of STING, present in about one-third of the population, appeared to neutralize the harmful effects of the COPA mutation.

To confirm their theory, the scientists needed both affected and unaffected family members to participate in the testing. Letasha, Kristina and Betty immediately volunteered. The researchers then analyzed DNA samples from 26 COPA patients and their healthy relatives. They also conducted CT scans and blood tests to ensure that unaffected members did not have any hidden symptoms. When the findings were all clear, it was revealed that all the healthy individuals had HAQ-STING, while none of the COPA patients did. This was the first known case of a common gene variant completely protecting against a severe genetic disease.

Encouraged by this discovery, researchers tested HAQ-STING’s effects in a lab setting. They introduced it into diseased lung cells from COPA patients, and the cells returned to normal function.

Way Ahead

Shum believes HAQ-STING could lead to game-changing treatments, including:

• Prenatal gene therapy for babies diagnosed with COPA Syndrome before birth
• Aerosol delivery of HAQ-STING for adults, directly targeting the lungs

Before publishing their findings, Shum called Betty with the news—her own HAQ-STING gene had protected her from the disease. He also informed Letasha and Kristina, who were overwhelmed with relief and joy.

“We always believed Dr. Shum would get to the bottom of it,” said Letasha. “This discovery is going to change lives.”