Two clinical trial participants—one with β-thalassemia and one with sickle cell disease—appeared to benefit from the gene-editing treatments with minimal side effects, according to the companies.

By unraveling the molecular underpinnings of inherited blood disorders, the Boston Children’s Hospital researcher has provided the basis for therapies now being tested for beta-thalassemia and sickle cell disease.

James Herrick, a Chicago doctor, was the first to describe sickled red blood cells in a patient of African descent.

The Germany-based study will test an ex vivo genome-editing therapy for the inherited blood disorder β-thalassemia.

Researchers say they have sufficient in vitro and animal data to apply for human testing.

Once implanted in mice, the edited stem cells produced normal hemoglobin.

The sickle cell anemia mutation may protect against malaria by preventing the parasite from sending dangerous proteins to the red blood cell surface.