Family battles rare disorder that affects 200 children worldwide.

Twin 5-year-old girls living with a disease known as "Childhood Alzheimer's" are among the first in the country being treated for their condition after the FDA granted special permission to use an experimental drug, reports the Associated Press. They'll receive intravenous infusions of the drug cyclodextrin, a sugar compound that has been successful in laboratory studies.

Addi and Cassi Hempel of Reno, Nevada are fighting for their lives and their memories due to Niemann-Pick Disease -- otherwise known as "Childhood Alzheimer's." It's a rare disorder that damages internal organs, causes early onset dementia, and is inevitably fatal.

Never heard of it? Neither had we. Pediatrician Dr. Gwenn says, "In Niemann-Pick Type C, the body can't break down cholesterol, so it ends up in places that it shouldn't -- like the brain. With a buildup of cholesterol in the brain, the child will develop symptoms similar to Alzheimer's over time."

How worried should moms be? "This is so rare that most moms shouldn't worry," Dr. Gwenn says. But if anyone else in your family has this condition or you belong to one of the high-risk groups, then she recommends seeking genetic counseling and testing.

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