Alexander Disease : A Rare Defect Involving The Nervous System

1661 Words7 Pages
Alexander Disease Alexander Disease is a rare defect involving the nervous system. It is part of a classification of uncommon genetic disorders called leukodystrophies that affect the central nervous system by interfering with the growth and nourishment of the myelin sheath. Myelin sheath shields nerve fibers and promotes rapid transmission of nerve impulses. If myelin is not properly nurtured, the transmission of nerve impulses can become disrupted causing serious impairment of nervous system functions. Although a majority of cases with early onset exhibit a distinct deficiency in the formation of myelin, white matter defects are sometimes not detected in cases accompanying later onset. Contrary to its classification, the universal characteristic among all Alexander disease cases is actually the presence of atypical protein compounds called Rosenthal fibers. They present themselves in a particular type of glial cell found in the central nervous system known as an astrocyte. Glial cells provide nutrients for neurons, absorb dead neurons, and physically reinforce their structure. Rosenthal fibers are composed of substantial quantities of glial fibrillary acidic proteins (GFAP). GFAP is known to sustain the mechanical strength of astrocytes, but in this case it is a defect in GFAP that has been found to interfere with the function of astrocytes and ultimately causes the leukodystrophy. When tested on mice, the mutation of GFAP caused a new, toxic effect, rather

More about Alexander Disease : A Rare Defect Involving The Nervous System

Open Document