What is DNA?

DNA

DNA is the biological recipe that differs each person from everyone else. It is responsible for determining every feature in our bodies.

Human DNA consists of 23 chromosomes, each of which contains roughly a little over one thousand genes.

These genes in turn are compromised of a strand of thousands to millions of nucleotides. A nucleotide is a combination of a phosphate group, a sugar base, and a nucleic acid.

The four different bases, which are adenine, thymine, cytosine, and guanine, determine the exact nature of the nucleotide.

The particular order of these nucleotides determines the identity of a gene.  The replacement of even one nucleotide can cause a drastic difference in what kind of protein that gene tells the cell to produce.  Scientists think that such a change may be responsible for causing some people to develop Fuchs Endothelial Corneal Dystrophy.

Replacing one base (adenine, thymine, guanine, cytosine) for another can lead to the production of incorrect proteins and possibly disease. From http://ghr.nlm.nih.gov/ghr/picture/dna

DNA’s Applications to Fuchs Dystrophy

Fuchs Endothelial Dystrophy is believed to be arise from genetic mutations — “mistakes” in the coding of DNA.  More about DNA and mutations can be found at the Genetics Home Reference website, which is maintained by the U.S. National Library of Medicine, a division of the National Institutes of Health.  http://ghr.nlm.nih.gov/info=mutations_and_disorders/show/gene_mutation

Fuchs Dystrophy appears to be an autosomal dominant genetic disorder.  This means that it only takes one “Fuchs gene” from one parent to give a child Fuchs.  Usually at least one member of each generation is affected.

Research is currently being done to investigate this probable link between Fuchs Dystrophy and its likely mutation. The actual process is complicated, but the basis behind it is rather simple:

1. Take samples of DNA from two family members, one with the disease and one without it;
2. Focus on a particular gene whose functions are distorted by Fuchs Dystrophy;
3. Sequence the DNA;
4. Compare the DNA from the healthy person with the DNA from the diseased one.

Though there are over 30,000 genes in the human DNA, researchers have been able to narrow down the probable genes that harbor this disease to roughly 40 genes.  These 40 genes are currently being sectioned, and each fragment is being carefully analyzed with special machines.

A couple of the genes that cause a very rare type of Fuchs (early onset Fuchs) have been identified.  One of these was discovered at the Wilmer Eye Institute and named FECD.  You can read the entire paper here.