Rare disorder demands quick intervention
Siblings’ disparate outcomes are emblematic of how important an early diagnosis can be
By KELLY BOTHUM • The News Journal • October 12, 2010
Both of Donna Sawyer’s children were born with the same life-threatening immune disorder that left their tiny bodies susceptible to infections from even minor viruses, bacteria and fungi.
Today, her 12-year-old son, Austin, is a Boy Scout, baseball player and straight-A student at Conrad School of the Sciences. Her daughter, Alex, who is 15, has cognitive deficits and is in special education classes at Christiana High School. She has gone through years of speech, physical and occupational therapies, yet still struggles with physical limitations on her left side caused by a stroke she suffered at 9 months old.
The difference between her children’s outcomes, Sawyer said, is early detection. Austin and Alex have severe combined immunodeficiency, or SCID, a rare condition in which patients are essentially born without a functioning immune system. As a result, they can’t fight off the germs the same way as someone with a functioning immune system. Without treatment, children born with SCID rarely live past their 2nd birthday.
Alex was 9 months old before she was diagnosed with SCID, believed to occur once in every 100,000 births. In that time, she battled repeated ear infections, diarrhea and vomiting, and never seemed to get better. After her diagnosis, she underwent a bone marrow transplant and slowly began to recover, but not before her body went into organ failure. She spent two months on life support and suffered a massive stroke that left her with permanent damage to her brain and the left side of her body.
Because of Alex’s diagnosis, Austin was screened at birth for the genetic disorder. Like his sister, he underwent a bone marrow transplant at Duke University, but suffered none of the complications she did.
“Today, his quality of life is much better than Alex,” said Sawyer, who lives in Newark. “Life is going to be a struggle for her.”
Sawyer hopes to save other children from what Alex experienced by getting SCID added to the panel of diseases newborns are screened for in Delaware.
Bubble boy disease
SCID was once known as “bubble boy disease.” Patient David Vetter gained worldwide attention in the 1980s after a movie was made about his experiences living more than a decade in a sterile bubble to reduce his vulnerability to infection. Vetter died in 1984 after an unsuccessful bone marrow transplant.
Dr. Stephen McGeady, interim chief of the division of allergy and immunology at Alfred I. duPont Hospital for Children, calls SCID a “pediatric emergency” because of the severity of illness in babies born with the rare group of inherited disorders.
In a normal developing immune system, specialized cells mount a response to what the body perceives as foreign invaders. Antibodies attack these invading viruses, bacteria and fungi, generating an immune response. But in patients with SCID, there are defects in these immune responses, so children can’t fight off even minor infections. Children with SCID are at a higher risk of chronic ear infections, thrush and other yeast infections, as well as bronchitis and pneumonia.
Because they lack natural immune defenses — imagine a fighter going into battle without protective armor — these kids seem to stay sick, as they are bombarded with viruses and bacteria that their bodies cannot defend against, said McGeady, who has seen just two cases of SCID in more than a decade at the hospital. In both cases, the patients eventually died.
SCID is one of about 150 kinds of primary immune disorders that are believed to affect 250,000 people in the United States, said Christine Belser, senior director of programs and education at the Immune Deficiency Foundation in Towson, Md.
“One of the biggest problems is that people get a very late diagnosis because only the symptoms are treated. The root cause is not,” Belser said. “You can’t take away the harm that has been done. The important thing is having this diagnosis as early as possible so the right kind of treatment is done.”
From the time Alex was about 2 months old, she was always sick. Initially, the first-time parents chalked up the problem to their daughter being in day care. They kept taking her to the pediatrician, but she never seemed to improve despite medications and antibiotics. By the time she was diagnosed at 9 months old, Alex was critically ill. She wound up at Duke University Medical Center, where she had a bone marrow transplant. Her mother was her donor.
“They told us she would not make it through the night. It was just gut-wrenching,” said Sawyer, who said the bill for Alex’s care was more than $1 million. “Little by little, she made it through and started to improve.”
Since their transplants, Alex and Austin, who also had a transplant with marrow donated by Sawyer, show no immunological problems associated with SCID. They return annually to Duke for immune studies.
Sawyer hopes to prevent other children from experiencing what Alex did. Adding SCID to the list of diseases newborns are screened for in Delaware would make that possible, she said, even if it means only one or two children would be diagnosed.
Nationwide, state newborn screening programs test about 4 million babies each year for genetic and metabolic disorders. These are conditions that wouldn’t otherwise be apparent in a newborn. About 12,000 babies are screened annually in Delaware.
In January, a federal advisory committee recommended the addition of SCID to the uniform newborn screening panel. Six months later, the American Academy of Pediatrics made a similar recommendation.
In order to add SCID to the newborn screening panel in Delaware, the state would have to pass legislation mandating the test, said Leah Jones, chief of the maternal and child health bureau with the Delaware Division of Public Health. Delaware currently tests for more than 30 disorders, using a sample of blood taken from a heel stick on the baby.
DPH supports adding SCID testing to the panel, and is investigating the cost of adding equipment and staffing for the additional laboratory testing, Jones said.
Sawyer knows the impact of early diagnosis, both in terms of intervention and medical cost. She hopes to convince state health officials as well.
“It’s something that makes such a difference,” Sawyer said. “I see my kids and I know that.”
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