Twelve-year-old Jerry appears to be like many other boys his age.

But if you talk with Jerry, don't be surprised if he makes unusual sounds during your conversation.

Jerry has Tourette's syndrome, a rare disorder of the central nervous system. Symptoms of Tourette's Syndrome usually include uncontrollable body motions and verbal utterances, says Dr. Robert Rodnitzky, a neurology professor in the University of Iowa Carver College of Medicine.

"Uncontrollable grunting, swearing, shouting, kicking, blinking, and shrugging are some visible symptoms of Tourette's," Rodnitzky says. "These involuntary movements and vocalizations are called tics.

The verbal tic is one of the most well-known indicators of Tourette's Syndrome, Rodnitzky says. Grunts, shouts, and swearing can leave an indelible impression on people witnessing that behavior, he notes.

"It can be embarrassing for a Tourette's patient, especially when the verbal tics are socially unacceptable words," he says. But informed professionals, such as school teachers, can help to promote understanding of the illness and discourage negative responses to Tourette's patients from other persons.

Tourette's syndrome is believed to be caused by a chemical imbalance in the brain. In many patients there appears to be a genetic predisposition to the illness because other family members also may have tics, he says. Four of five Tourette's patients are male.

The symptoms usually begin to appear sometime between 5 and 15 years of age, and usually improve and sometimes disappear after adolescence.

Another challenge for Tourette's patients is the frequent occurrence of attention-deficit/hyperactivity disorder, he adds.

No one ever dies from Tourette's Syndrome, Rodnitzky says.

Tourette's sufferers can learn to adjust to their illness.

"In a vast majority of cases, the most traumatic aspect of the disease is the social stigma it places on its victims. Some people become isolated and avoid social situations," Rodnitzky says. "But many others learn to adjust and with the help of medication can lead a relatively normal life."

Drugs may alleviate some of the symptoms, but currently there is no cure, Dr. Rodnitzky says.