All babies in the United States get newborn screening before they leave the hospital. Newborn screening looks for rare but serious and mostly treatable health disorders. Babies with these disorders often look healthy. But if the condition is not diagnosed and treated early, a baby can develop lasting physical problems or intellectual disabilities, or may even die.
The federal Advisory Committee on Heritable Disorders in Newborns and Children (ACHDNC) recently voted to recommend adding X-linked adrenoleukodystrophy (X-ALD) to the Recommended Uniform Screening Panel (RUSP). This recommendation now needs to go to the Secretary of Health and Human Services for her review and consideration.
X-ALD is a genetic disorder that occurs mostly in boys. In this disorder, the fatty covering (myelin) that insulates nerves in the brain and spinal cord is broken down. This reduces the ability of the nerves to relay information to the brain. X-ALD can cause serious and permanent disability or death. The only effective treatment is early identification by newborn screening, and stem cell therapy (bone marrow or cord blood transplantation), sometimes along with other life-saving treatments.
X-ALD is due to a gene change, or mutation, on the X chromosome. The X and Y chromosomes are responsible for gender. Girls have two X chromosomes (XX). They inherit one from their mom and one from their dad. Boys have an X and a Y chromosome (XY). They inherit the X from their mom and the Y from their dad. Since boys have only one copy of the X chromosome, they will have only one copy of the X-ALD gene mutation, and they will develop X-ALD. Because girls have two copies of the X chromosome, they will only have one copy of the gene mutation (inherited from their mom). A single copy of the altered gene usually does not cause any symptoms of X-ALD. Although some girls can have health problems associated with the condition, they are often mild and usually appear at a later age.
X-ALD has not been officially added to the Recommended Uniform Screening Panel. We will keep you updated. In the meantime, here is a very personal story about newborn screening and why it is so important:\