Leukodystrophy: A Rare but Fatal Genetic Disorder

Leukodystrophy: A Rare but Fatal Genetic Disorder

Did you know that the word Leukodystrophy originated in Greece, from the words Leuko (white), dys (disorder), and trophy (Growth)? These words, when combined describe a group of diseases that have an impact on the growth of white matter (myelin).

Leukodystrophy is a group of genetically transmitted disease that affects the myelin of the central nervous system. Myelin is the white matter inside the brain and on the spinal cord that protects and covers our nerves, just like insulation is used in a house to protect it from the heat and cold. This disease affects the myelin production and breakdown (In rare cases, it can become too thick). When the myelin is damaged, the nerve tissue below it can't operate or function in its normal way. Unfortunately, Leukodystrophy diseases are continuous, and tend to progressively get worse over a victims life.

Leukodystrophy can be received in two different ways, but only genetically, depending on the parent's chromosomes, and the type of leukodystrophy. The first way that the disease could be transmitted is in relation to gender (The X Chromosome is affected). Males are 50% likely to become sick and carry the defective chromosome. Females cannot actually become sick in this transmission type, but have a 50% chance of carrying this defective chromosome. The reason that males can only become sick is because of the X chromosome (gender). Look at the diagram below.

In the above diagram, we can see that the girl on the far left will be a healthy carrier, since the healthy X chromosome will compensate for the defective one received from the mother. The boy on the left, however, does not have a healthy X chromosome to make up for the defective one. As a result, he will be affected with the disease.

Diagram & Caption From- http://www.leukofoundation.com/faq.html

The other way in which Leukodystrophy can be received is called autosomal recessive. This phrase means that it has no relation to the gender chromosome, and that both parents have to carry the defective gene for the disease to be passed on. This transmission doesn't have any relation to gender (X chromosome). One of four of the children of carrier parents will receive the actual disease, and another One of four children will be completely healthy and not even carry a defective gene. The other two of