Gene Disorder Screen Benefits Baby Boys, Girls Equally: Study

It was previously thought that the deadly form of the birth defect was easier to spot in girls.

TUESDAY, Feb. 26 (HealthDay News) -- Universal screening of newborns improves the detection of a deadly genetic disorder in both girls and boys, according to a new study.

The findings challenge the current belief about the detection of the severe salt-wasting form of congenital adrenal hyperplasia (CAH). It has commonly been thought that boys are at greater risk for delayed diagnosis, the researchers explained in the Feb. 25 online edition of The Lancet Diabetes and Endocrinology.

CAH is the most common adrenal disorder in children and affects the production of the hormone cortisol in the adrenal glands. The salt-wasting form of the disorder affects one in 10,000 to 15,000 newborns and can lead to neurological damage or intellectual disability, and death if not diagnosed and treated early enough.

Salt-wasting CAH is associated with overproduction of androgen hormones. This can result in girls being born with abnormal genitals while boys generally appear normal, the study authors noted.

Most developed countries routinely screen newborns for congenital adrenal hyperplasia, but that is not the case in all countries, including Australia and the United Kingdom.

"Until now it was believed that newborn boys with the severe salt-wasting form of CAH were at much greater risk of delayed diagnosis and early death than girls, as girls are more often diagnosed shortly after birth because of ambiguous genitalia, whereas boys appear normal. However, our data show that both boys and girls are missed by physical examination -- even in a country such as Sweden with a developed health care system -- and that newborn screening improves survival in both sexes equally," senior researcher on the study, Anna Nordenstrom, of the Karolinska University Hospital Huddinge in Sweden, said in a journal news release.

For their study, the researchers analyzed all known cases of congenital adrenal hyperplasia in Sweden between 1910 and 2011. There was a significant increase in diagnosed cases in the 1960s and 1970s, following the discovery of the first effective treatment in 1950 and increased awareness of CAH and its symptoms. The number of diagnosed cases increased again after the introduction of newborn screening in 1986.

The author of an accompanying journal editorial, Bridget Wilcken, of the Children's Hospital at Westmead and University of Sydney in Australia, wrote that "there is little doubt that screening for the disorder fulfills the essential criteria for screening -- it is, after all, a potentially lethal disorder -- and a 2010 study in the U.K. concluded that a case can be made for screening. Certainly, pediatric endocrinologists from Australia agree."

More information

The U.S. National Library of Medicine has more about congenital adrenal hyperplasia.