A noninvasive way of screening newborns for Gaucher disease, using dried blood spots, is both efficient and feasible, according to a recent Chinese study.
Besides making early treatment possible so as to prevent irreversible damage, screening can provide information about the number of affected individuals in a region to inform health policy. But starting such a program will likely spur debate, because Gaucher-related mutations in people often do not result in disease symptoms.
The study, “Successful newborn screening for Gaucher disease using fluorometric assay in China,” was published in the Journal of Human Genetics.
Researchers at Shanghai Institute for Pediatric Research and Shanghai Jiao Tong University School of Medicine in China analyzed dried blood spots of 80,855 newborns. The approached used, called the ﬂuorometric method, detects the activity of beta-glucocerebrosidase (GBA) — the enzyme lacking in Gaucher disease.
First, they tested the method on blood spots from 116 healthy volunteers, 19 Gaucher disease patients, and 19 carriers of the mutation causing Gaucher who had no symptoms.
The evaluation showed that the method could discriminate between healthy people and patients, who had lower enzyme activities than both carriers and healthy controls.
The first screening of newborns detected low enzyme activity in 11 babies. These samples were retested with similar results.
Of the 11 children, eight were considered to be carriers or normal individuals with relatively low enzyme activity. Three, however, had low enzyme activities that made researchers suspect disease. New blood samples ruled out two of the children as possible Gaucher patients, as enzyme activity was normal upon re-testing.
The last infant went through further genetic testing, which confirmed that the child had mutations in its beta-glucocerebrosidase gene. The researchers identified one known mutation and a novel one, inherited from each parent.
Despite the positive identification, the child remained free of symptoms at two years of age. Physicians are continuing to monitor for disease symptoms.
Researchers concluded that the positive predictive value for Gaucher disease in the screening was 33.33 percent.
Nevertheless, Gaucher screening of newborns raises concerns. Some argue that the stigma of a genetic diagnosis may do more harm than good, particularly since many people with Gaucher disease-related gene mutations never develop symptoms.
But a recent study found that the benefits of screening likely outweigh potential harms.