Surprising test results
At her first visit, the pulmonologist ordered a blood test for a genetic disorder, just in case. “I really don’t think you have this,” she recalls him saying, “and you really don’t want to have it.” McCathern, who was contending with another bout of pneumonia, gave it little thought, returning a few weeks later for a follow-up appointment.
She remembers that the doctor first glanced at her test result, then did a double take before telling McCathern that it was positive. He ordered it repeated, along with an additional test. Several weeks later, the results were in and they were definitive, upending a quarter-
century of repeated misdiagnosis.
McCathern had an inherited disorder called alpha-1 antitrypsin deficiency, which can cause disabling and progressive lung and liver disease. She also learned that she had the most serious type — ZZ — which results from the inheritance of two damaged genes, one from each parent. She had never had asthma.
“Everything stopped,” McCathern recalled. The pulmonologist told her she would need weekly infusions of an intravenous drug and, most likely, a lung transplant by the time she was 62. Her mother, a nurse, was appalled by the diagnosis and, McCathern said, initially called the doctor “a quack. I’d say she was in denial. It was a pretty big shock.”
McCathern herself was“pretty upset.” She wondered why the many doctors she had seen over the years had never thought to test her for the disorder.
First described in 1963, the condition is among the most common inherited disorders affecting Caucasians, usually those of Northern European descent, and is caused by the deficiency of a protein made in the liver that allows the lungs to function properly. About one in 2,500 Americans isbelieved to be affected, according to the National Human Genome Research Institute. Those who inherit one normal and one damaged gene are considered carriers and may live healthy lives, particularly if they do not smoke. Among the 100,000 Americans with the most severe form, studies have estimated that only about 6 percent know they have the condition.
Although infants can show symptoms, most “alphas” develop initial signs of the disease, often shortness of breath, between ages 20 and 50. There is no cure; treatment involves weekly infusions of intravenous medications including Prolastin, which replaces the missing protein. Some patients require lung transplants; others develop liver cancer or may need liver transplants.