We assessed the frequency of gene editing associated with CTX001 in CD34+ HSPCs obtained from 10 healthy donors. High frequencies of allelic editing (mean [±SD], 80±6%) were observed and maintained across all subpopulations of CD34+ cells, including long-term hematopoietic stem cells. In edited CD34+ HSPCs that were isolated and edited at clinical scale and differentiated toward the erythroid lineage, fetal hemoglobin levels increased to a mean of 29.0±10.8%, as compared with 10.5±5.2% in unedited control cells (Figure 1C).

Question

We assessed the frequency of gene editing associated with CTX001 in CD34+ HSPCs obtained from 10 healthy donors. High frequencies of allelic editing (mean [±SD], 80±6%) were observed and maintained across all subpopulations of CD34+ cells, including long-term hematopoietic stem cells. In edited CD34+ HSPCs that were isolated and edited at clinical scale and differentiated toward the erythroid lineage, fetal hemoglobin levels increased to a mean of 29.0±10.8%, as compared with 10.5±5.2% in unedited control cells (Figure 1C). 
can you summarise the main point in this evidence such as what crisipr is used to fix or improve what single gene mutation or disorders

GPT 3.5 · Answer

The main point of this evidence is that high frequencies of gene editing with CRISPR were observed in CD34+ HSPCs from healthy donors, leading to an increase in fetal hemoglobin levels in edited cells. This gene editing approach is used to potentially treat or improve disorders related to abnormal hemoglobin production, such as sickle cell disease or beta thalassemia.