The Rundown
- Each of us has 46 chromosomes, which are actually set up in pairs of two. We receive 23 from mom and 23 from dad. Twenty-two of those pairs are known as autosomes (defined for being non-sex chromosomes, which will be important to know for later). The last pair determines just that, whether we will be a male or a female and are therefore named as such, sex chromosomes. If your confused, obtain two pieces of string, thread, etc. Lay them out and cross one of the other forming an X. Loop the string lying over the top under like your making a pretzel. At this point, repeat the same step with the two strings above the swirl you already have to form a knot. You should have created something with a large knot with four appendages stemming from that knot. This is generally what a chromosome looks like, below.

- Each chromosome contains DNA, which acts as our genetic blueprint. Each DNA molecule can be composed of 10,000 to 1,000,000,000 nucleotides. Now imagine that you were to take a 0.5 mm mechanical pencil and write a repeating code over the whole chromosome you just created. Our DNA works with four repeating nucleotides (C,G,A,T), so as you write your blueprint for your chromosome keep it to four letters as that will relay all of the necessary information for the body. But remember, it is just a blueprint.
- We need a way to take our blueprint and somehow make it functional. This is known as the central dogma. Suffice it to say, several components are involved in reading the blueprint to produce a messenger RNA, which carries the information to another processing center that reads that information and ultimately makes a protein. Translation…the DNA is read (similar to the Leapfrog Tag Reading System below) and that information is then placed into, let us say, an easy bake oven. The oven produces a protein which has functional capabilities to move throughout the body and do work.
Now, if rewind a few paragraphs and become a little more specific with the information carried by the chromosome, segments of the repeating code can be called genes, because the have a specific destination or function as to what they will be. Just think back to the blueprint, we will contain specific information for each part of the building. Each gene carries blueprints with specific instructions for making proteins. Those proteins then act as the body’s building blocks. In our case, this specific protein called FGFR3 (Fibroblast Growth Factor Receptor 3) has mutated by at least one nucleotide base. Translation…the four lettered code you put on your own homemade chromosome somehow becomes changed which means it will be read differently and ultimately will come out as something different from your easy bake oven.- The FGFR3, from what scientists believe, becomes overactive leading to altered development of the long bones, which is what has happened in Baby W’s case.

