Genetics

I decided a few weeks ago to do a very standard screening test to see if Baby G has any markers for Down Syndrome. That's when I got to watch the cutest fetus in the world wriggle and squirm on the ultrasound, as you saw in the video. The test involved taking a measurement of Baby's head (the nuchal fold) and drawing a blood sample to see if a certain protein was present. It took a while for my doctor's office to get back to me, but the good news is it looks like the Babe Gaultney has a very low risk of having Down Syndrome or serious congenital heart problems.

To borrow from the American Pregnancy Association's website, this test is approximately 85 percent accurate with a false positive rate of 5 percent. This means that:

• Approximately 85 out of every 100 babies affected by the abnormalities addressed by the screen will be identified.
• Approximately 5 percent of all normal pregnancies will receive a positive result or an abnormal level.
• A positive test means that you have a 1/100 to 1/300 chance of experiencing one of the abnormalities.

In related news, I'm taking a genetics and ethics course at SMU right now. My professor is convinced she is going to terrify me with all of the chromosomal disorders we're going to talk about, but I am truly not apprehensive about the course. I figure there is absolutely nothing I can do about it now, if the baby were to have some abnormality, so why get worked up? The most interesting chromosomal disorder I have learned about so far is called Lesch-Nyhan's, where an X chromosome mutation causes the sufferer to self-mutilate. An M.D. who is a student in the class said he treated a case where the child would try to bite all of his fingers off and bash his head against walls. People afflicted with this disorder have to be strapped into beds, sedated, kept in padded rooms... It's terrible, and truly amazing how important balance is in our bodies. If you have an extra set of chromosomes, a missing set, or if a chromosome is bigger or smaller than it should be, it can throw everything off.

The course has also got me thinking about dominant and recessive traits. What eye color is Baby most likely to have? As it turns out, since Brad and I both have hazel eyes, it's awfully hard to predict. Interesting, anyway!

This is sort of a rambling post. I'll end by saying we're really grateful that Baby G seems to be healthy so far!