taylor@hplabsc.UUCP (Dave Taylor) (10/02/86)
This article is from hpccc!mcgregor@hplabs.HP.COM (Scott McGregor) and was received on Thu Oct 2 08:05:12 1986 [a response to Mike Burman, with the quoted section edited out] Perhaps, instead Dave was referring to a story that was on the radio recently. Another technique is being experimented with in Japan, to screen out children with birth defects that are linked to sex chromosomes such as hemophelia. If parents test positive for such chromosomal defects, they can go to an artificial insemination lab. The lab runs the sperm in the centerfuge, and the statistically heavier X-chromosome (female) sperm drop to the bottom. Sperm can then be syringed up from the bottom with a pretty good chance of selecting only the X-chromosome sperm and then through standard artificial insemination techniques a child can be concieved with is very likely to be a girl. Unfortunately, skimming the top to get all Y-chromosomes doesn't seem to work as well, so the probabilities for conceiving a boy when using this technique are not quite as good. However, this may not be as much of a problem, since sexually tied genetic defects are more likely to affect males than females. This is because females have two X chromosomes, and the chance of both chromosomes being defective is less than males who have a single X and single Y chromosome, either of which could be defective and would not be masked by another non-defective chromosome. At least, that is the way I heard it.