Inherited Metabolic Disorder More Common Than Thought

But it's not clear whether newborns need routine screening for SCADD

TUESDAY, Aug. 22, 2006 (HealthDay News) -- An inherited metabolic disorder called SCADD, which can cause developmental delay and other problems, is more common than previously believed, Dutch researchers report.

But experts are divided on whether newborns should be routinely screened for the disease.

People with SCADD (short-chain acyl-coenzyme A dehydrogenase deficiency) aren't able to oxidize fatty acids because a certain enzyme is missing or not functioning properly. This can result in developmental delay, low blood sugar levels (hypoglycemia), and epilepsy, according to background information in the study.

SCADD is only passed on to a child when both parents carry the faulty gene.

This University of Amsterdam study included 31 SCADD patients and 8 relatives of people with the disorder.

Reporting in the Aug. 23/30 issue of the Journal of the American Medical Association, the researchers concluded that about one in 50,000 babies are born with SCADD.

"Most patients presented before the age of three years, with non-specific, generally uncomplicated, and often transient symptoms," the study authors wrote. "Developmental delay, epilepsy, behavioral disturbances, and hypoglycemia were the most frequently reported symptoms."

However, "because SCADD does not meet major newborn screening criteria, it is not suited for inclusion in newborn screening programs at this time," the authors concluded.

However, an editorial in the same issue of the journal said the data in this study does not provide enough information to rationalize the exclusion of SCADD from standard newborn screening.

"Long-term studies comparing children identified by newborn screening with clinically identified children are needed," wrote Susan E. Waisbren of Children's Hospital Boston.

"Only through comprehensive, long-term research will a rational, fair, and universal newborn screening policy become reality," Waisbren concluded.

More information

The U.S. National Library of Medicine has more about SCADD.

SOURCE: JAMA, news release, Aug. 22, 2006
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