Diagnosis

X-ALD and AMN are both diagnosed through a simple blood test to determine the quantity of VLCFA in the sample. A high blood level of VLCFA combined with typical disease symptoms confirms the diagnosis in males, although a false negative result (i.e., a normal VLCFA blood level) occurs in about 20% of women who are proven carriers of the disease. A DNA-based blood test can also be performed to precisely identify carriers through genetic testing. Other forms of testing include: diagnostic testing, carrier screening, and prenatal diagnosis. The Kennedy Krieger Institute has created a newborn screening system to detect abnormally high levels of VLCFA from small amounts of blood. This technique is currently being performed on a larger sample to see whether this test is accurate enough to potentially be used as a newborn screening method for X-ALD.