The path to GMO hu­mans

As re­search into hu­man gene edit­ing ad­vances, so­ci­ety has to grap­ple with tough eth­i­cal is­sues.

Los Angeles Times - - OPINION -

In a process that can be likened to the cre­ation of GMO crops, sci­en­tists have edited genes in hu­man em­bryos in order to elim­i­nate a mu­ta­tion that causes thick­en­ing of the heart wall. The em­bryos were cre­ated solely for the sci­en­tists’ study and will not be im­planted. None­the­less, the re­search of­fers hope that in years ahead, science could pre­vent many se­ri­ous ge­netic dis­eases at the stage in which peo­ple are a mi­cro­scopic clus­ter of cells in a petri dish. What’s more, be­cause those edited genes would be car­ried forth into new gen­er­a­tions, the dis­ease might even­tu­ally be elim­i­nated al­to­gether.

Is this a glo­ri­ous new fron­tier or a trou­bling sit­u­a­tion? Un­equiv­o­cally, the an­swer is yes to both.

The re­search re­sults by an in­ter­na­tional team of U.S., Chi­nese and South Korean sci­en­tists were enor­mously ex­cit­ing med­i­cally. Be­yond the tech­ni­cal achieve­ment in­volved, the team’s work has­tened the ar­rival of a rev­o­lu­tion­ary form of treat­ment: re­mov­ing genes that can lead in­ex­orably to suf­fer­ing and pre­ma­ture death.

But there is also a great deal we still don’t know about how mi­nor is­sues might be­come ma­jor ones as peo­ple pass on edited DNA to their off­spring, and as peo­ple who have had some genes al­tered re­pro­duce with peo­ple who have had other genes al­tered. We’ve seen how se­lec­tively breed­ing to pro­duce one trait can un­ex­pect­edly pro­duce other, less de­sir­able out­comes. Re­mem­ber how grow­ers were able to cre­ate toma­toes that were more uni­formly red, but in the process, they turned off the gene that gave toma­toes fla­vor?

An­other ma­jor is­sue is the ethics of ad­just­ing hu­mans ge­net­i­cally to fit a fa­vored out­come. To­day it’s her­i­ta­ble dis­ease, but what might be seen as un­de­sir­able traits in the fu­ture that peo­ple might want to elim­i­nate? Short stature? Shy­ness? Klutzi­ness?

To be sure, it’s not as though every­one is likely to line up for gene-edited off­spring rather than just hav­ing ba­bies, at least for the fore­see­able fu­ture. The pro­ce­dure can be per­formed only on in vitro em­bryos and re­quires pre­ci­sion tim­ing.

But even with this early study, prob­lem­atic is­sues al­ready are ev­i­dent. Gene edit­ing isn’t the only method to pro­tect against cer­tain hered­i­tary con­di­tions such as hy­per­trophic car­diomy­opa­thy, which was “edited out” in this study. Chil­dren stand a 50% chance of in­her­it­ing the con­di­tion; if a cou­ple pro­duces sev­eral em­bryos through in vitro fer­til­iza­tion, half of those al­ready would the­o­ret­i­cally be free of the mu­ta­tion, and those are the ones that would be se­lected for im­plan­ta­tion. Gene edit­ing made the process more ef­fi­cient, but it did not of­fer hope where there was none, Jen­nifer Doudna, a molec­u­lar and cell bi­ol­o­gist at UC Berke­ley, ob­served.

In fact, six months ago the Na­tional Acad­e­mies of Science, En­gi­neer­ing and Medicine rec­om­mended that sci­en­tists making ge­netic changes that would be passed down to fu­ture gen­er­a­tions should limit their work to dis­eases for which there are no other rea­son­able treat­ments. The most re­cent em­bryo study be­gan be­fore that rec­om­men­da­tion was de­liv­ered.

That’s em­blem­atic of the real prob­lem: Pub­lic pol­icy and bioethics have not caught up with the science of ge­netic in­ter­ven­tion. Yes, fed­eral money can’t be spent on DNA re­search in­volv­ing hu­man em­bryos. FDA approval would be needed for any ac­tual hu­man ther­a­pies, which would be years off.

Still, the tech­nol­ogy is ad­vanc­ing more rapidly than so­ci­ety’s dis­cus­sions about hu­man ge­netic en­gi­neer­ing, the specter of eu­gen­ics and even the seem­ingly mun­dane topics of who will own the patents on cus­tom­ized genes and who will have ac­cess to gene edit­ing once it is ap­proved.

The an­swers aren’t easy, but the dis­cus­sions have to take place and de­ci­sions need to be made, probably through an in­ter­na­tional con­ven­tion that in­cludes gov­ern­ments, re­searchers, physi­cians and con­sumer ad­vo­cates. Tak­ing the re­search to the next level should mean ex­per­i­men­ta­tion with an­i­mals rather than hu­mans. They should then be fol­lowed for gen­er­a­tions to see whether un­ex­pected health is­sues arise. Gene edit­ing on hu­mans should be in­tro­duced one step at a time, start­ing with the most dis­as­trous dis­eases and con­di­tions that can­not be tack­led in any other way, then tracked long term to en­sure safety.

We all would love to elim­i­nate dis­abling de­for­mi­ties, painful con­di­tions that shorten lives or ge­netic mu­ta­tions that pre­dis­pose us to var­i­ous fa­tal dis­eases. Al­though science has a long way to go be­fore such mir­a­cles are achieved, re­search is mov­ing fast. It’s paramount that we get hu­man gene edit­ing right rather than just get­ting it soon.

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