Neonatal Adrenoleukodystrophy
I decided to post about a very rare genetic disorder known
as neonatal adrenoleukodystrophy. Most people have never heard of this rare
disorder. This is genetic disease that I am very familiar with because my
cousin was diagnosed with neonatal adrenoleukodystrophy at the age of 6 months
and sadly died at the age of three. By all appearances Andy was a normal
newborn but it wasn’t long before my aunt and uncle noticed that something was
wrong. Initially the pediatricians told my aunt and uncle that everything was
fine and not to worry. Andy did not respond to visual cues or sound. Very soon
after birth it was determined that Andy was deaf and blind. He was missing all
of the milestones children should hit by the age of 6 months. Andy could barely
hold his head up and could not sit up or role over on his own. It was a mystery
to my family until he went to a specialist and it was determined that he had a
very rare condition called neonatal adrenoleukodystrophy. This genetic disorder
affects about 1 in every 50,000 births. This disorder is characterized by the
breakdown or loss of the myelin sheath surrounding the nerve cells in the brain
which causes dysfunction of the adrenal glands. In class we learned that the myelin
sheath is responsible for the transmission of the electrical impulses along the
axon. The breakdown of the myelin sheath affects one’s ability to transmit information
and this explains why my cousin was unable to see, hear, roll over or even sit
up. Unfortunately, this particular form
of leukodystrophy is fatal and there is currently no cure. For this reason my
family has been very involved with promoting awareness and supporting fund
raisers. Because this disorder affects the nerves and adrenal glands this is a
disease that will get progressively worse. This specific form of leukodystrophy
is caused by a mutation in the PEX5 gene. For an individual to have this
disorder they must have two copies of the mutated PEX5 gene. Both my aunt and
uncle were carriers of this mutated PEX5 gene. My aunt and Uncle gave birth to
another son several years later and were very lucky not to have passed along
this disorder to their second son. Because they were both carries of the
recessive mutated gene PEX5 they have a 50 % chance of having a child with the
disorder. I found the topic of this blog post interesting not only because of
my personal connection but also because of how this disorder relates to
multiple topics leaned about and discussed throughout this class. During this
class we discussed at length the transmission of recessive alleles and the pedigree
analysis and genetic counseling used. We
also discussed the function of the myelin sheath on the neurons axon and what
this is responsible for. Currently there is research being conducted using stem
cell transplantation using umbilical cord cells and bone marrow cell. Unfortunately
these treatments can only slow this degenerative process of the myelin sheath deterioration.
The most effective way to prevent this disorder is understanding genetic
testing for the recessive alleles.
Work Cited:
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