Diagnosis and Testing
How do I get tested for X-linked adrenoleukodystrophy?
The first diagnostic test for adrenoleukodystrophy is measuring very long chain fatty acids (VLCFA) in the blood. This is typically diagnostic for the condition. DNA testing of the ABCD1 gene may also be used to identify the genetic change in the individual. Testing is available at several different labs in the United States. A list of these labs can be found at the Genetic Testing Registry.
- Steinberg, S., Moser, A., Raymond, G. X-Linked Adrenoleukodystrophy. Gene Reviews. Online database. Updated April 2015. http://www.ncbi.nlm.nih.gov/books/NBK1315/
- X-Linked Adrenoleukodystrophy. Genetics Home Reference. Updated July 2013.https://ghr.nlm.nih.gov/condition/x-linked-adrenoleukodystrophy
- Genetic Testing Registry: Adrenoleukodystrophy. http://www.ncbi.nlm.nih.gov/gtr/tests/?term=C0162309[DISCUI]&condition=C0162309&test_type=Clinical&certificate=CLIA%20Certified&display_string=Adrenoleukodystrophy
More Diagnosis and Testing Content
Is there newborn testing for X-linked adrenoleukodystrophy?
Some states, including New York, California, Minnesota, and Connecticut test for X-linked adrenoleukodystrophy (ADL) at birth. Other states are in the process of adding ADL to their testing panel. In February 2016, Secretary of the Department of Health & Human Services, Sylvia Burwell, approved the addition of adrenoleukodystrophy to the federal government's list of diseases recommended for state newborn screening programs, the Recommended Uniform Screening Panel (RUSP). This may lead many other states to include adrenoleukodystrophy in their newborn screening programs. Advocating for newborn screening is the goal of many support groups, such as the Myelin Project. To find out which disorders your state's newborn screening looks for, please visit Baby's First Test. This website can provide you with a link to your state's newborn screening website.
If you have reason to believe your infant is at risk for adrenoleukodystrophy, speak to your physician about whether newborn testing would be helpful or how that could be arranged.
Is there more than one type of test for adrenoleukodystrophy?
There are two main types of testing to diagnose adrenoleukodystrophy: measuring very long chain fatty acids and DNA testing of the ABCD1 gene. Looking for the very long chain fatty acids in the blood should be sufficient to determine a diagnosis of adrenoleukodystrophy in most cases. If there is question, genetic testing of the ABCD1 gene can be performed. DNA testing of ABCD1 can also be useful for carrier testing, testing other family members, or prenatal testing. A genetic counselor can help you discuss and obtain genetic testing. Genetic counselors can be found on the National Society of Genetic Counselors website.
Who else in my family should I test for adrenoleukodystrophy?
Further testing should start with the mother of a boy with X-linked adrenoleukodystrophy, or both parents of a daughter thought to be a carrier. Based on parental status, the need to test siblings or other relatives can be established. A woman who is a carrier may want to inform her sisters or female cousins in particular. A genetic counselor, geneticist, or other physician can look at your family tree to help determine which relatives would be good candidates for testing and the best order to test these relatives. To find a genetic counselor near you who can discuss t genetic testing, visit the National Society of Genetic Counselors Find a Genetic Counselor website.
Can women use the same blood test to be diagnosed as a carrier for X-linked adrenoleukodystrophy?
Approximately 80-85% of women who are carriers of X-linked adrenoleukodystrophy will have increased very long chain fatty acids (VLCFA), but approximately 15-20% of carrier females will have normal levels of VLCFA. For these women, DNA testing will show if they have the same genetic change as their affected child. DNA testing for a carrier is best done when the genetic change has been identified in the affected individual. Testing for the amount of VLCFA and genetic testing will require two different blood samples as the same lab may not perform both tests.
Does it matter if you test blood versus saliva versus a biopsy for adrenoleukodystrophy?
Adrenoleukodystrophy testing, both biochemical and DNA testing, is typically done as a blood test.