Neonatal screenings boost diagnosis of congenital adrenal hyperplasia

It has been established that congenital adrenal hyperplasia is due to 21-hydroxylase deficiency resulting in cortisol and aldosterone deficiency. Recent study results from Swedish researchers suggest that male and female infants with the severe form of the disorder are often clinically missed, and neonatal screening equally improved survival rates among both sexes.

Sebastian Gidlöf, MD, PhD, and colleagues conducted a retrospective, population-based cohort study to assess the effect of historical medical improvements in the care of patients with the disorder over time and to determine the effects of neonatal screening in the patient population. They collected data from Statistics Sweden, a database which holds medical information from 1749 to 2011.

According to data, the CYP21A2 genotype was identified among 490 (81%) of 606 patients with the disorder born between 1915 and 2011. Researchers wrote that the incidence of congenital adrenal hyperplasia in Sweden increased during the 20th century, from fewer than one patient per million live births between 1910 and 1920, to more than one patient per 9,000 live births between 1990 and 2000. They also detected a major increase in the incidence per decade beginning in the 1950s, they wrote. Moreover, during the 1960s and 1970s, this incidence increased significantly from one in 37,000 to the current one in 8,800 patients.

“By the end of 2011, 2.7 million infants had been screened, representing 99.8% coverage of all newborn babies in Sweden (population 9 million),” the researchers wrote.

Further data indicate an increase in the salt-wasting form of congenital adrenal hyperplasia in both sexes after the introduction of neonatal screening in 1986. This incidence ranged from 114 (47%) of 242 patients between 1950 and 1985 to 165 (57%) of 292 patients between 1986 and 2011 (P=.038), they wrote.

There was a higher prevalence for diagnosis among women compared with men for the non-classic form of the disorder, according to researchers.

In an accompanying commentary, Bridget Wilcken, MBChB, of Sydney Children’s Hospitals Network and the University of Sydney, said Gidlöf and colleagues’ data show the increase in incidence over time, and that further research is necessary.

“The Swedish study underlines what can be learned from long-term follow-up, good record keeping, and registers. This type of activity should not only be encouraged but also funded if we are to make the best use of our accumulated experience,” Wilcken wrote. “At the same time, we should remember that for any long-term study, data collected at the beginning might not be entirely comparable with those collected toward the end. Medical diagnostic and therapeutic expertise moves on, so we need to draw conclusions with care.”

Gidlöf and colleagues wrote that improvements to surgical and psychological care of this patient population will remain a challenge in the future.

For more information:

Gidlöf S. Lancet. 2013;doi:10.1016/S2213-8587(13)70007-X.

Wilcken B. Lancet. 2013;doi:10.1016/S2213-8587(13)70009-3.

Disclosure: The researchers report no relevant financial disclosures.