FALMOUTH, Maine - Until their sixth birthday, Brigid and Katie Cooleen were mirror images of each other.
Today, it's not hard to tell the 16-year-old identical twins apart.
Brigid is chubby and 4 inches shorter, with a pacemaker in her chest and a ventilator in her bedroom to make sure she breathes in her sleep.
The honor student from suburban Falmouth suffers from ROHHAD, a rare brain disorder that strikes children, triggering sudden obesity and severe breathing problems.
She's even thinking about attending college out of state -- a quest for independence that makes her the best hope for parents of younger ROHHAD patients like Marisa Carney of Bayport on Long Island.Brigid lives with her parents, sister and older brother in a 250-year-old farmhouse about 15 miles northeast of Portland.
At 6, she suddenly began gaining weight -- more than 5 pounds a month. Her cheeks and belly rounded, her fingers swelled. Her lips were blue each time she emerged from the pool at school swim meets.
"We were like, 'Wow, that water must be cold," recalls Brigid's mother, Liz, 47, a hospital receptionist. The Cooleens now know the blue lips were a sign their daughter was lacking oxygen.
One doctor initially attributed Brigid's health problems to overeating, but Liz refused to believe it. She marched the entire family into his office.
"Look, no one in this family is obese," she proclaimed.
Then, one morning a few weeks later, Paul Cooleen struggled to rouse his daughter for summer camp. "She was hardly breathing," he recalls.
They rushed her to the emergency room. Her oxygen levels, tests showed, were dangerously low. She wound up staying in intensive care for nearly a month. A long line of specialists examined her only to walk away stumped.
"How can so many things go wrong with a child and no one know what's wrong?" says Paul, 46, a Manhattan bond broker.
The breakthrough came when an endocrinologist called ROHHAD experts in Chicago. There, Brigid underwent a marathon of testing to make the diagnosis, instantly becoming a prized research subject -- along with her sister. How the twins' genetic paths diverged could yield valuable clues in the search for a cure.
'In a good place'
Brigid's weight gain eased when she was 10, but major hurdles remain.
She must sleep hooked up to a ventilator; covering the tracheotomy hole in her throat during the day with a favorite scarf adorned with peace signs.
Like an elderly person, she had to have a pacemaker implanted to regulate her heartbeat. She's had spinal surgery to correct the small bones in her back where a noncancerous tumor caused by the disease was pressing.
Out of necessity, she counts every calorie. Joining her mother, she's on a Weight Watchers diet, and now, at 5-foot-4, weighs 165 lbs., down from 190.
Although her parents still use a baby monitor to watch over her late at night, Brigid is independent and has taken charge of most of her medical care.
Before getting into bed, she hooks herself up to the ventilator perched on an antique dresser.
"You kind of get used to it after a while, I guess," she says.
Before the diagnosis, Brigid was on her school's swim team. She can't compete in sports anymore, but she does the next best thing, helping coach her athletic sister's field hockey team.
She's devoting herself to artistic passions: painting, printmaking and drawing. With her parents' support, she hopes to be able to go out of state for college in two years -- ideally one with a university medical center nearby.
Brigid seems happy, her mother says, adding, "I think she's in a good place right now."
There's no telling what's around the corner, but Brigid is doing her best to stay positive.
"You can't take it too hard," the teen says. "You have to find good things and other ways to deal with it."