Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site aecom.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!think!harvard!bbnccv!bbncca!linus!philabs!aecom!werner From: werner@aecom.UUCP (Craig Werner) Newsgroups: net.bio,net.med Subject: Re: Sickle-Cell Anemia population genetics Message-ID: <1868@aecom.UUCP> Date: Thu, 22-Aug-85 01:03:35 EDT Article-I.D.: aecom.1868 Posted: Thu Aug 22 01:03:35 1985 Date-Received: Sun, 25-Aug-85 06:28:50 EDT References: <191@tekig5.UUCP> <314@kitty.UUCP> <678@cybvax0.UUCP> <1858@aecom.UUCP> <192@husky.uucp> Organization: Albert Einstein Coll. of Med., NY Lines: 26 Xref: watmath net.bio:249 net.med:2181 > > What's a CBW? I've been reading this group [.bio] and wondering. > Also, is sickle-cell anemia really a defense against malaria? > If so, how does it work? Isn't the cure worse than the disease? > Hemoglobin(Sickle), or HbS, doesn't form the polymers that result in sickling. When mixed with normal HbA, it prevents HbA from sickling too by ruining the 'crystal' as it forms. That's how it works. HbS also lacks the site for the malarial parasite (its the same site.) It's not sickle cell that is selected for. That is fatal. It is the carrier state - 1 sickle cell gene, 1 normal gene. Sickle cells carriers are reasonably non-anemic. There are four genetic outcomes, 1 with HbA/HbA - these are more prone to malaria (without malaria, these are the healthiest people), 1 with HbS/HbS - these die young of sickle cell. The other two are HbS/HbA - one of each --> these people are resistant to both sickle cell and malaria. They perpetuate the gene pool, and keep the Sickle gene around. I have no idea what a CBW is, but I have doubts of the mental stability of the original poster, so I don't consider it too important. -- Craig Werner !philabs!aecom!werner "The world is just a straight man for you sometimes"