Origins of Sickle Cell

broylesr — Sat, 25 Jul 2009 00:35:02 +0000

Increasing fetal hemoglobin in people with homozygous sickle cell alleviates all symptoms of SCD.
The Google map shows four independent genetic origins, or haplotypes, of SCD in different regions (ellipses) and the subsequent migrations of populations (white arrows). The solid white arrow is to signify the forced migration of Western Africa peoples as slaves to the Western Hemisphere. The four haplotypes (Se = Senegal, Be = Benin, Bantu, and Arab-India) all have the sickle cell mutation in exactly the same gene location, but other genetic differences associated with the haplotypes result in differences in the severity of SCD. The Arab-India group has a second mutation that keeps a fetal hemoglobin (HbF) gene active after birth, such that HbF is up to 45% of the total Hb including sickle hemoglobin (HbS). People of the Arab-India haplotype with 30% or more HbF have no clinical manifestations of SCD, revealing that increased HbF can offer a “cure.” Decreasing HbS and increasing HbF by using gene regulation therapy is the basis of SCCF’s cure.

Globe image of Africa and Asia is copyrighted by Google Earth and is used with permission.

Facts About SICKLE CELL DISEASE (SCD)

broylesr — Sat, 25 Jul 2009 00:34:01 +0000

Zoo Walk 2008 with SCCF posters and SCCF Board Member Gary Bricker in the background, and SCDAA Member Debra Jackson (center) and co-workers in the foreground.

In the United States, SCD affects primarily people of African descent. But this pattern of prevalence is changing, with increasing numbers with SCD being found among Hispanics, Native Americans and Caucasians. SCD affects a large percentage of people in Central America as well as significant numbers in the Carribean and in South American countries such as Brazil. In the Mediterranean countries, SCD is found in people of Portuguese and Spanish descent, as well as in French Corsicans, Sardinians, Sicilians, mainland Italians, Greeks, Turks and Cypriots. Prevalence is increasing in other European countries such as France, Germany, and the UK, due to both to newborns (new incidence) as well as migration from African countries. Sickle cell disease also affects large numbers of people in Middle Eastern countries, Indian and Asia. And approximately 70 percent of the global number of SCD cases are in Africa. SCD is the most frequently occurring genetic disease on earth.

Approximately 1 in 12 African-Americans are carriers of the Sickle Cell Trait. Many more are afflicted worldwide.

The average life expectancy of someone who suffers from SCD in America is about 40 years. Where treatments are not readily available, they often die in early childhood. In underdeveloped countries, 60-to-80 percent of babies`with SCD die before two years of age.

SCD causes lung tissue damage, pain episodes and stroke. The blockage of blood flow caused by sickled cells also causes damage to most organs including the spleen, kidneys and liver.

People who suffer from SCD have mostly hemoglobin S, an abnormal form of hemoglobin. However, all people are born with hemoglobin F, or fetal hemoglobin, which does not sickle. Normally, by six months of age, hemoglobin F expression switches to hemoglobin A, normal hemoglobin, or in the case of someone who suffers from SCD, hemoglobin S.

The Sickle Cell Cure Foundations’s cure is based on introducing a protein that causes a reversal of this switch, from HbS back to HbF. There are some people in whom this occurs naturally, and they do not suffer any of the symptoms of sickle cell disease.

http://www.bu.edu/sicklecell/research.html
http://www.sicklecelldisease.org
http://www.curesicklecell.org
http://sickle.bwh.harvard.edu/scd_history.html
http://www.pbs.org/wgbh/evolution/library/01/2/l_012_02.html
http://www.umm.edu/blood/sickle.htm
http://www.innvista.com/health/ailments/anemias/sickhist.htm

Sickle Cell Cure Foundation » Sickle Cell Disease

Origins of Sickle Cell

Facts About SICKLE CELL DISEASE (SCD)