Recently, researchers form Dana-Farber found that a small change of DNA can avoid some genetic defects of SCD, this research was published on nature on September 16.

Sickle cell disease is a kind of genetic disease, which is caused by the mutation of hemoglobin. This disease is common in Africa, and also takes place in United States. People with sickle cell disease will be seen with chronic hemolytic anemia and ache, and they are easy to be infected.

The key is an erythroid enhancer of human BCL11A. It decides results of erythrocyte turning. Some will turn to the mature form of hemoglobin, and others will become unaffected fetal hemoglobin which can fight against the mutation. Patients with unaffected fetal hemoglobin has lesser symptoms.
Read more at: http://www.cd-genomics.com/blog/index.php/new-discovery-about-crispr-treatment-of-scd/