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An unpublished paper by a Chinese genetics team released Tuesday shows just how careless and rash the researchers were in editing the DNA of twins allegedly born in 2018, according to peers in the field.
A journalist at MIT Technology Review obtained a copy of "Birth of Twins After Genome Editing for HIV Resistance" - rejected for publication by the journals Nature and JAMA - and released portions of it Dec. 3.
The Chinese twin girls Lulu and Nana (pseudonyms), allegedly born in 2018, are the first living humans born with edits to their genes, edits which supposedly make the twins HIV-resistant. The research team used CRISPR Cas9, a revolutionary gene-editing tool that is still prone to errors and unexpected results. Rather than celebrating the project as a triumph of medicine, the research community excoriated its lead biophysicist for ethical recklessness and sloppy procedures. He Jiankui led the project and has been its public face, though the paper's author list included nine other scientists.
The MIT journalist solicited comments from genetics researchers and a law professor about the paper, all of whom harshly criticized it.
First among the major problems with the paper: there is no evidence the babies were even born at all. Second, assuming the twins were born healthy as the paper asserts, there's no evidence the mutations scientists induced will actually protect the twins from HIV.
Furthermore, the actual gene mutations didn't match the intended mutations, and one twin had an "off-target" gene mutation that scientists didn't bother to examine and assumed wouldn't be a problem. The paper also showed researchers didn't bother to check whether each cell in the gene-edited embryos had the same mutations, meaning that the girls may have some cells with the mutations and other cells without, or with totally different mutations scientists didn't notice, according to the report.
And the summary of the paper touts results that contradict the actual data from the project.
"The summary goes well beyond what the data in the paper can back up," according to the Technology Review article. "Specifically... the team didn't actually reproduce the known mutation. Rather, they created new mutations, which might lead to HIV resistance but might not. They never checked to see, according to the paper."
The fertilization and gestation happened through the in-vitro fertilization process, but no fertility doctors are listed in the study. This and evidence reported by outlets like The Wall Street Journal suggest He tricked some fertility doctors into participating in his unethical experiment by switching blood samples and by other means, according to the MIT magazine report.
How Do Scientists Edit Genes?
The team who edited Lulu and Nana's genes used a revolutionary new gene-editing tool called CRISPR Cas9. CRISPR (Clustered regularly interspaced short palindromic repeats) are repeating sequences of genetic material in certain single-celled organisms, according to MedicineNet. These segments of genetic material, along certain enzymes, constitute the basis of a gene editing system, which is also referred to as "CRISPR" (pronounced "crisper").
This technology can be used to target and edit specific stretches of genetic code, permitting the modification of genes in living cells. The technology has the potential in the future to correct mutations at precise locations in the human genome to treat genetic causes of disease, according to MedicineNet.
This tool is less than a decade old and is still imperfect, however, leading to sloppy edits and unintentional consequences in the lab, which is a major reason the medical and ethical establishment were so quick to condemn He's work.
What Are Medical Options for People With Genetic Diseases?
If you are susceptible to an inherited disease or if you have a genetic condition in your family and you want to have children, your current options include genetic counseling. Genetics professionals are healthcare professionals with specialized degrees and experience in medical genetics and counseling. Genetics professionals include geneticists, genetic counselors and genetics nurses, according to the National Human Genome Research Institute (NHGRI).
Your health care provider may refer you to a geneticist - a medical doctor or medical researcher - who specializes in your disease or disorder. A medical geneticist has completed a fellowship or has other advanced training in medical genetics. While a genetic counselor or genetic nurse may help you with testing decisions and support issues, a medical geneticist will make the actual diagnosis of a disease or condition. Many genetic diseases are so rare that only a geneticist can provide the most complete and current information about your condition, according to the NHGRI.
Along with a medical geneticist, you may also be referred to a physician who is a specialist in the type of disorder you have. For example, if a genetic test is positive for colon cancer, you might be referred to an oncologist. For a diagnosis of Huntington disease, you may be referred to a neurologist, according to the NHGRI.
Genetic professionals work as members of health care teams providing information and support to individuals or families who have genetic disorders or may be at risk for inherited conditions. According to the NHGRI, genetic professionals may perform the following services:
- Assess the risk of a genetic disorder by researching a family's history and evaluating medical records.
- Weigh the medical, social and ethical decisions surrounding genetic testing.
- Provide support and information to help a person make a decision about testing.
- Interpret the results of genetic tests and medical data.
- Provide counseling or refer individuals and families to support services.
- Serve as patient advocates.
- Explain possible treatments or preventive measures.
- Discuss reproductive options.