Sofia Jarvis is 4 years old and her left arm is paralyzed. Her parents say she's coping remarkably well, but does have some tough moments.
"We call her left arm 'Lefty' in order to make sure it's still part of her body," said Jessica Tomei, Sofia's mom.
"When we go to the park and you can just see, like when a little kid goes to the park, she loves to climb and there's certain things she can't do once she's there," said Jeff Jarvis, Sofia's dad.
Sofia is one of five Bay Area children who've come down with a rare, polio-like illness over the past 18 months. Researchers say her case is mild. Some of the other children, ages 2 to 16, are paralyzed in more than one limb.
"Our suspicion is this is a virus, but that's unproven," said Keith Van Haren, M.D., a pediatric neurologist at Lucile Packard Children's Hospital.
Van Haren and Emmanuelle Waubant of UCSF have been working on identifying the cause.
"The prognosis that we've seen so far is not good. Most of the children we've seen have not recovered use of their arm or leg," said Van Haren.
Researchers say they aren't trying to scare anyone, emphasizing that these cases are extremely rare, but they do want to get the word out. In addition to the five confirmed cases, they are investigating 15 others. Researchers say some of the children first showed symptoms of the common cold.
As for Sofia, odds are she'll never regain use of her arm. A sobering thought, but this sweet little girl from Berkeley is displaying maturity far beyond her years.
"Sofia told me all we need is love," said Tomei.