For the second time in her life, Tessa Koller listening to a doctor deliver bad news. A defect in her coronary artery required surgery. She was 25.

She'd lived with heart disease all her life, gone into surgery as a 10-week-old infant, endured years of mysterious blackouts, breathing problems, learning delays and depression.

Later that night in March 2009, Tessa lay in bed, her mind running. At 4 a.m., she awoke from a nightmare in which a friend who died at age 22 had spoken to her. Tessa rose and began cleaning her Milwaukee condo. In her closet, she found photographs of her mother's garden in St. Charles, Ill. The flowers looked so beautiful. She had always meant to paint them.

At 7 that morning, she did exactly that, beginning the most creative period of her life. She painted in the mornings and sewed at night, rushing to fit a lifetime.

Most of her life Tessa did not know why she was sick. She had heart problems — the early surgery was to treat a hole in her heart and an abnormal formation of the aorta. But these didn't seem to explain the learning delays, the speech difficulties, the weak immune system.

Finally her mother took her to Children's Hospital and in March 2008, she received a diagnosis. She had 22q11.2 deletion syndrome, something missing in a chromosome.

Despite its strange name, 22q11.2 is one of the most common disorders involving chromosomes. An estimated 1 of every 4,000 babies is born with 22q, as the disorder is often called. Tessa had never heard of it, and for 24 years, no doctor had tested her for it.

"It's a really common problem and it's commonly missed," said Jack Routes, chief of the Division of Asthma, Allergy and Immunology at Children's Hospital and the Medical College of Wisconsin.

The syndrome involves the deletion of several genes on Chromosome 22, especially one called TBX1. This gene plays a crucial role in early development, serving as a kind of band director in a process that ferries different cells to different places in the body to develop. Symptoms seem to be all over the map, one reason why the syndrome is difficult to recognize.

The month before Tessa's surgery date in August 2009, her doctor called and said he wanted to do one more evaluation to be absolutely sure the surgery was required. Tessa went to the hospital for detailed pictures of the artery.

As the anesthesia was wearing off she could see her mother and her stepfather talking excitedly to the doctor. Then they rushed in: "You don't need the surgery! You don't need it!"

Even without the surgery, Tessa must be careful with her health. That's fine. She continues with her art and fashion, and thinks it can help others.

With the help of her mother and stepfather, she also is spreading the word about 22q with the nonprofit "Tessa Koller Knowledge Is Hope" fund.

"I want people with my condition to have opportunities to model and to feel beautiful and just to be happy in their skin."