I have this recurring dream. We're in the middle of some terrorist act, some crazy event where we can't find our loved ones and somehow, my 12-year-old daughter Corey and I have become separated. She's with someone-a neighbor I think-but I can't find her. I keep checking my watch. If I don't get her next drink to her in time-the "medicine" she needs every two hours to keep her blood sugar stable-she could die.

Somehow, miraculously (this is a dream after all), I find her and am able to give her the simple Argo cornstarch and water mixture that she needs to stay alive. But it's the last solution I have, meaning Corey has about two hours more to live unless I can find more. I'm drenched in sweat and riddled with anxiety as I scour desperately through my war-torn town searching for a store that hasn't been decimated. I'm trying not to show Corey how frantic I am as I clasp her hand tightly and lead her through the rubble. She starts to complain that she is tired and I know time is running out. And then I wake up.

Corey has Glycogen Storage Disease (GSD) type la, a rare metabolic disorder which means her body is missing a liver enzyme necessary to convert the stored form of sugar (glycogen) into the usable form (glucose). Glucose is the essential source of energy for the brain and is the necessary fuel for every cell in our bodies. Because this enzyme is missing, she must be fed constantly in order to get the sugar required for her body to function. It's a genetic defect, and my husband and I both carry the recessive gene. At the time I was pregnant, in 1992, there was no testing for this disease. Nor would we have even thought to be tested since there is no history of GSD in our families.

We spent six weeks at Columbia Presbyterian Hopsital in New York City when she was seven months old trying to determine what was wrong with her after she had vomited nearly every formula on the market. Then another three weeks at Boston Children's when she was 18 months to get her on the cornstarch regime. We tubed her for three and a half years, until finally we went to the Kennedy Krieger Center in Baltimore, where we spent another six weeks teaching her behavior modification techniques so she would drink her cornstarch, though we still tube-fed her at night. It was our first step towards a "normal" life.

The gastrostomy tube is our life-saver. It's a plastic tube that's been surgically attached to her stomach so that we can open and close it at will. It's how we can feed Corey when she won't take things by mouth-which happened a lot when she was little. Or when she's sleeping or sick.

Having GSD also means adhering to a restricted diet: no sucrose, fructose, lactose or glucose, so Corey can never chew an apple, taste a carrot, or lick an ice cream cone. Because she gets so much cornstarch during the day, she is never hungry, which makes mealtimes frustrating. And as with any other chronic disease, there are additional complications: physical and occupational therapy, a learning lag, self-esteem issues.

There will never be any marathons for GSD or benefit concerts or celebrity-studded black tie events. It's an orphan disease-just like others you've never heard of like progeria or alpha-1 antitrypsin deficiency or neurofibromatosis. And like most rare conditions, there is no cure.

Despite the strides we've made in 12 years, I'm always focused on what's to come. It's become part of my internal makeup. I have no idea what kind of mother I'd be if Corey were "normal." As it is, I sit on the sidelines of many a "mom" conversation. It's difficult to concentrate on homework concerns, playdate escapades, or sports accomplishments when I'm consumed with triglyceride levels, uric acid, heart function, and cholesterol. The fact is, I'm scared all the time for Corey.

Corey calls me a worrywart, but I can't help it. Unlike other mothers who can fly out the door to run an errand with nothing more than their wallets, I can't leave the house without Corey's next drink-plus a few extras in case of spillage.

Corey's like an old-fashioned hour glass that runs out of fuel when the sand disappears. At night, we've been able to stretch her time limit to four hours, which means there are feedings at 11:30 P.M.., 3:30 A.M.. and 6:30 A.M. I do the 3:30, which means I sleep really well between 10 P.M. and 3:30 A.M., but then I'm usually up worrying about all that I need to do the next day. When I finally drag myself out of bed at 6:30 A.M., I feel like I haven't slept at all.

There are also the psychological issues, which are harder to "fix." Because Corey's liver is distended, pushing out her other organs and making her stomach large in proportion to her body, she already thinks she's fat. The "you have a medical condition" explanation doesn't work on a budding teen who only wants to fit in with the crowd.

It's these times-often in The Limited dressing room after she's thrown a handful of shirts in my lap that our eyes lock and I want so badly to switch places with her, to say "Give me the missing enzyme. Let me deal with this disease," especially since we often leave the store empty-handed, as she tries to hide her tears.