Rebecca Alexander has summited Mount Kilimanjaro.
She skydives, bungee jumps, swam 1.2 miles from Alcatraz to San Fransisco Bay, biked 600 miles for charity, and regularly competes in military-grade obstacle-course races.
She is also completely deaf and slowly going blind.
The extreme athlete and full-time psychotherapist has Usher syndrome, a genetic condition that slowly robs sufferers of hearing and sight. To raise awareness about the condition, Alexander will take the mound at Fenway on Thursday to throw out the first pitch.
“There’s so much love and pride in Sox fans. If we could take a quarter of that enthusiasm, and apply it to our community with helping Usher syndrome, we’d really be on the right track,’’ said Alexander, author of “Not Fade Away: A Memoir of Senses Lost and Found.’’
At 39, Alexander hears with surgically implanted cochlear implants. Her field of vision is 10 degrees, as opposed to people with normal vision who have a field of 180 degrees.
A winner of an American Foundation for the Blind 2016 Helen Keller Personal Achievement Award (past winners include Stevie Wonder, Ray Charles, and Patty Duke), Alexander has aimed to raise awareness for Usher syndrome in a number of ways.
She has done a TED Talk and has appeared on the “Today’’ show and “NBC Nightly News,’’ both of which she filmed with her brother, NBC News national correspondent Peter Alexander.
She has been featured in Shape, Women’s Health, and Marie Clare.
Born along with a twin brother, Daniel, in 1979, Alexander first showed signs of the syndrome at 12 when she had trouble seeing the blackboard.
A specialist diagnosed her with retinitis pigmentosa. The family was told she’d be totally blind by 30.
Then at 18, in a freak accident, she fell out of a second-story window, breaking her back and nearly every bone in her body. After spending a year recovering, and months in a wheelchair, she was able to attend the University of Michigan — only to experience unrelated ringing in her ears.
The tinnitus led to a new diagnosis: Usher syndrome type III. She was slowly going both deaf and blind.
Alexander didn’t slow down, however. She enrolled at Columbia University, earned master’s degrees in Clinical Social Work and Public Health, and turned to fitness.
“As I continued to lose both my vision and hearing, I found the more I was able to strengthen my body. I couldn’t control that I was going deaf and blind, but I could control being strong,’’ she said.
Aside from her work as a psychotherapist, she teaches fitness classes, works out, travels for speaking engagements — she was just in Thailand — and is soon off to Chicago to perform in a theatrical documentary, “Silent NO MORE.’’
Her pitch at Fenway is one of a series of Major League Baseball pitches she’s thrown recently in an effort to raise awareness. Her doctor, Daniel M. Laby, an ophthalmologist specializing in sports vision, works with the Red Sox, among other major league teams.
“I’ve always loved motiving people to push themselves. . . . Having Usher syndrome has given me more purpose than I ever thought possible,’’ Alexander said. “I’ve always gained tremendous inspiration from the capacity and resilience of the human spirit.’’