How is Krabbe Disease Diagnosed?
If Krabbe disease is not detected through the newborn screening process then it’s often diagnosed once symptoms are displayed outwardly. Diagnosis will likely entail clinical observation of signs and symptoms. A number of diagnostic tests exist, and one or more of them are performed if symptoms observed are consistent with the disease.
A lumbar puncture (spinal tap) may be performed to obtain cerebrospinal fluid protein levels. Elevated protein levels can indicate some sort of abnormal process in the central nervous system.
Brain imaging may be performed by MRI (magnetic resonance imaging) or CT scan (computed tomography). Both can be utilized to produce images that can help identify abnormalities in the brain. Typically, the MRI produces the best image to detect abnormalities that may be associated with Krabbe. An MRI may show increased or decreased signal intensity in white matter in the brain.
Nerve conduction studies can be performed to detect the velocity at which signals travel along the nerve. Due to the destruction of myelin associated with Leukodystrophies, nerve conduction may be at a reduced velocity or display abnormal patterns.
Krabbe disease is caused by a deficiency of the GALC enzyme. A blood or skin sample can be tested to measure GALC enzyme activity. Little or no activity can result in presence of the disease.
Genetic testing can determine particular mutations in our DNA that prevent the body from developing and maintaining healthy myelin.
The above tests will not indicate how quickly the disease will progress. Many mutations of the GALG gene exist, and the specific combination of mutations can cause symptoms and the rate of progression to vary significantly for each case.
Having Krabbe disease screening included as part of the Newborn Screening process allows Krabbe to be diagnosed before symptoms develop. At this point there are possibilities of live-saving procedures.