Angus, 34, died "due to her heart and TIA (transient ischemic attack or mini-stroke)," according to her website.
Acromegaly or gigantism is a rare pituitary disorder that causes the body to produce too much growth hormone. It affects about 20,000 Americans.
Since 2010, when ABCNews.com first told her story, Angus had continued to grow to be more than 7 feet tall and weigh 400 pounds. Before the disease began, she stood only 5 feet 8 inches tall and weighed 135 pounds.
"Her tremendous love of our community could only be matched by her generosity of spirit," said Wayne Brown, founder of the Acromegaly Community.
"No matter how tired or sick she was, you could always count on Tanya for a smile and a hug that was guaranteed to raise your spirits," said Brown. "Tanya's infectious laugh brightened up a room, simply by her presence. She always had time to say hi to one more person, even when she was too tired to do so. She was a hero to people around the world, simply because of her bravery and class, as she faced so many unknowns."
As her body grew larger, so did her heart, lungs, joints and other parts of her body. Soon she was being crushed by her own weight, and needed constant care from family and friends.
Her family was hopeful last year when new medication seemed to slow her growth.
Angus had grown so large that she could barely walk, and a swimming pool, where she could float, was the only place where she was without pain.
Her gigantism was caused by a tumor on her pituitary gland but radiation and three surgeries, in the end, did more harm than good. One 13-hour operation nearly killed her, and another caused a stroke that took away most of her hearing.
Her mother, Karen Strutynski, told ABCNews.com last year that Angus's acromegaly was the "worst in the world."
About 95 percent of the time, the condition is caused by a non-cancerous tumor on the pituitary gland, according to the Pituitary Network Association. Such was the case with Angus, but the tumor was wrapped around her carotid artery, and was inoperable.
As a result of gigantism, fluid accumulates in the body, causing stress on multiple systems. Patients are more prone to cardiac conditions, hypertension and diabetes. They suffer headaches and joint pain or premature osteoarthritis, and their mortality rate is two to four times that of the general population, according to medical advisers to the Acromegaly Community.
At 21, Angus was a beautiful young woman who rode horses, danced and had a boyfriend. But one day, she noticed changes: Her shoes didn't quite fit, her jeans were too tight and her hands got bigger.
"She was perfectly normal, but by age 22 she had grown three inches," said her mother. "Nobody knew what was going on."
Angus, who lived in Michigan and was a supervisor at a Walmart, began to worry when even her face and head got larger. Her bosses also noticed -- and fired her. And her boyfriend left when his parents began to ask, "Is she a man?'"
Tanya decided to return home in 2002. When her sister picked her up at the airport, she "freaked out," because she didn't recognize Tanya.
The doctor took one look and diagnosed acromegaly.
"Acromegaly Community's members all stand together in mourning of this wonderful woman," said Brown in a statement. "We love and loved her in a real and true fashion. And while we are saddened for the passing of such a wonderful person, everyone in our organization feels richer for having her in our lives....
"Rest in peace, dear princess."
For more information, go to Acromegaly Community.