FrancoiseBaylis

Cost and knowledge are important considerations. Right now, interventions in humans for somatic genome editing are in clinical trials. See, for example, https://www.ucsf.edu/news/2021/12/421901/sickle-cell-clinical-trial-aims-cure-disease-correcting-patients-mutated-gene Through research, we will learn more about the potential benefits and harms of this kind of intervention. An overarching worry is that if the research is successful the benefits will only accrue to a small subset of people who can afford the price tag.

I think it is really important to unpack the idea of a designer baby. Right now we have two kinds of designer babies: (1) so-called three-parent babies—children born of embryos created with genetic material from three people instead of the usual two and (2) so-called gene-edited (or genome-edited) babies—children born of heritable human genome
editing whose nuclear DNA has been genetically modified. On November 25, 2018, Jiankui He, who sometimes goes by “JK,” announced the birth of the world’s first CRISPR babies—twins, Lulu and Nana (pseudonyms). Since then a third child has been born. JK was jailed for three years for this research and was only released this Spring. In my book Altered Inheritance I details the potential benefits and harms of heritable human genome editing. I also engage with the supposed distinction between treatment and enhancement (spoiler alert -- I don't think this distinction holds up and I especially don't think we should assume treatment=good and enhancement=bad.

In addition to the science, it is also important to think about the ethics (but I wouldn't describe this as a bottleneck).

There is an important difference between "Making People Better" and "Making Better People".

There is wide agreement on the ethics of helping patients (persons who exist and are suffering) by offering therapeutic somatic genome editing. There is emerging debate about the ethics of in utero somatic genome editing on developing fetuses. There is considerable and sustained debate about the ethics of choosing the traits of persons who do not yet exist. Heritable genome editing involves the genetic manipulation of gametes, precursors to the gametes, early (one-day) embryos. It is about bringing into being, a being that do not yet exist. This is very different from trying to develop treatments for people who exist and have a debilitating condition.

Impossible to answer this question in the abstract -- much depends on what kind of health problems you are referring to. In the short term, there is the thought that it might be possible to use heritable human genome editing to change single gene disorders. This possibility raises a host of ethical issues.

Two recent international reports address this. One by the World Health Organization https://www.who.int/publications/i/item/9789240030060 and one by an International Commission of National Academies (free download https://nap.nationalacademies.org/read/25665/chapter/1) Both report conclude that research on heritable human genome editing is at best premature.

Considerable progress is being made with somatic genome editing technologies to treat cancers, inherited forms of blindness, blood disorders as well as neuromuscular and neurological diseases. Most of this research is in animal models. There are a few clinical trials in humans. Right now there is a lot of enthusiasm with research using CRISPR gene editing for sickle cell disease. https://www.npr.org/sections/health-shots/2021/12/31/1067400512/first-sickle-cell-patient-treated-with-crispr-gene-editing-still-thriving