Biotinidase deficiency

On its face, newborn screening is simply a good idea. Tests for conditions like phenylketonuria and congenital hypothyroidism that, left untreated, can cause death or lifelong disability are administered everywhere in the United States.

But the simplicity ends there. Questions arise about new technology that makes it possible to screen for many more conditions and about the ethics surrounding parental consent and the research use of test samples. And what should be done about the "screening gap" among states? Massachusetts, for example, tests for more than 10 conditions, while South Dakota only tests for 3. (See chart.) And if testing is expanded, who will pay?

In the August issue of Pediatrics (106 [2 supp.]:383-422, 2000) the report of an expert panel convened by the Health Resources and Services Administration and the American Academy of Pediatrics offers ample testimony to the complexity of these and other issues, if few concrete answers.

According to cochair Dr. Edward McCabe, the most impressive accomplishment of the Newborn Screening Task Force was simply the fact of consensus. "We had a very diverse group of individuals, representing a broad range of interests and philosophies, coming to the conclusion that we need a national agenda, a core group of tests that every baby in the [United States] should have. It's taken 10, 15 years to reach this point."

But which tests? On this question the task force was silent, and not everyone is happy with that. "It's a good report. Dr. McCabe and his group are to be congratulated on it," said Dr. Michael Katz, vice president for research at the March of Dimes Foundation. "But it didn't go as far as we would like it to have gone.

Dr. Katz, whose commentary is slated to appear in the September issue of Pediatrics, noted that the March of Dimes already advocates a specific panel of tests for all infants (phenylketonuria [PKU], congenital hypothyroidism, congenital adrenal hyperplasia, biotinidase deficiency, maple syrup urine disease, galactosemia, homocystinuria, and sickle cell anemia), and suggested that the task force should have done likewise.

"As multiorganization reports go, it was inconclusive," he said. "It's like an unfinished symphony ... and it should be finished."

On this last point there is little disagreement from those involved in the task force. "The intent was never to detail specific guidelines," Dr. McCabe said. "We didn't have all the individuals around the table to implement the specifics that the March of Dimes would have wanted."

The report is "a first step," said Dr. Peter van Dyck, director of HRSA's Maternal and Child Health Bureau. "We were getting the ball rolling." The next, he suggested, will be expert panels to deliberate further on the problematic areas identified in the report-including the question of a core group of tests. "We'd like to be well along in this process within a year," he said.

"Most of us feel that no matter how uncommon the disease, if there is a preventive mechanism or treatment available, we should consider testing for it," he said.

The report also recognized the need for technical standards, Dr. McCabe pointed out. "For PKU, for example, some states are using late 50s-early 60s methods, others the latest technology We must ensure that the quality of testing is appropriate for all babies."

In addition, he said, the development of new techniques such as tandem mass spectrometry and DNA analysis that have created "the potential for explosion in newborn screening" complicates the task of those setting guidelines. Tandem mass spectrometry can identify 20 or more conditions, not all of which can be treated effectively, Dr. McCabe observed.

"Some individuals in public health are concerned that the finite resources available for children with PKU and congenital hypothyroidism, for which we know the benefit, could be siphoned off for management of those who may not prosper even if a diagnosis is made," he said.

Although the issue of testing standards was the most visible, in fact the task force report addresses a far wider spectrum of "issues and challenges," including questions of informed consent and confidentiality and the need for public and professional education. A key motif, Dr. van Dyck noted, was that newborn screening cannot be seen in isolation, but "as part of an integrated medical care system" in which adequate follow-up must be ensured if testing is to have any value.

Among the most potentially problematic areas explored was economics--another subject that aroused criticism from the March of Dimes. "Unfortunately public health is financed by taxpayers' money and state governments must be good stewards of that money" Dr. McCabe said.

"If the government can afford to buy Stealth bombers, it can afford to buy child health," Dr. Katz of the March of Dimes maintained.

What the report did not confront directly was the underlying constitutional issue. Since newborn testing is a state function, how can national standards be enforced? As a practical matter, "States that don't achieve the standard [set forth in a national agenda], will be [medicolegally] liable," Dr. McCabe suggested. "If they elect not to screen for a disease and miss a diagnosis, the state will have to explain why it disregarded that part of the agenda."

COPYRIGHT 2000 International Medical News Group
COPYRIGHT 2001 Gale Group