Bloomberg View

A med­i­cal break­through the U.S. may miss • Slow­ing North Korea’s nukes

Bloomberg Businessweek (North America) - - Contents -

One of the most ex­cit­ing and promis­ing de­vel­op­ments in the his­tory of med­i­cal sci­ence may by­pass the U.S. if Congress fails to act. It needs to lift the ban on fed­eral spend­ing on re­search in­volv­ing hu­man em­bryos. Other gov­ern­ments are al­ready re­spond­ing to the progress be­ing made in ge­netic tech­nol­ogy. The U.K. has given re­searchers per­mis­sion to use a gene-cut­ting tech­nique called Crispr-cas9 to in­ves­ti­gate how hu­man em­bryos de­velop. Chi­nese sci­en­tists are wield­ing the same tool to see if it’s pos­si­ble to fix the gene re­spon­si­ble for beta tha­lassemia, a deadly blood dis­or­der. (So far, no.)

In the U.S., such stud­ies are al­lowed—but only if they are pri­vately funded. Not only is there the con­gres­sional ban but the Na­tional In­sti­tutes of Health has re­fused to fund re­search that uses gene-edit­ing tech­nolo­gies on hu­man em­bryos.

This pro­hi­bi­tion, un­for­tu­nate in it­self, poses a greater prob­lem: When ge­netic tech­niques ad­vance to the point where they might be used clin­i­cally—that is, to safely pre­vent dis­ease in hu­man em­bryos that progress to live births—the Food and Drug Ad­min­is­tra­tion won’t be able to li­cense them. This gives Congress an even more com­pelling rea­son to change course.

The FDA has pointed out this prob­lem: Its own ex­pert panel has rec­om­mended that med­i­cal sci­en­tists be al­lowed to pur­sue mi­to­chon­drial re­place­ment ther­apy, or MRT. This is an ex­per­i­men­tal ge­netic tech­nique that has the po­ten­tial to pre­vent de­bil­i­tat­ing, and some­times deadly, mi­to­chon­drial dis­eases with so-called three-par­ent em­bryos. (It sub­sti­tutes a healthy donor’s mi­to­chon­drial DNA for an em­bryo’s flawed ver­sion.)

For such tech­nol­ogy to move be­yond the lab­o­ra­tory and into ac­tual prac­tice, how­ever, the FDA would have to li­cense it, as if it were a drug or a med­i­cal de­vice. But the agency said Congress pre­vents it from “us­ing funds to re­view ap­pli­ca­tions in which a hu­man em­bryo is in­ten­tion­ally cre­ated or mod­i­fied to in­clude a her­i­ta­ble ge­netic mod­i­fi­ca­tion.”

And this is pre­cisely what MRT does: It mod­i­fies an em­bryo in a her­i­ta­ble way. By the same to­ken, the kind of hu­man DNA-edit­ing that Crispr is ex­pected to en­able—to al­ter genes re­spon­si­ble for dis­eases such as Tay-sachs, Hunt­ing­ton’s, and sickle cell ane­mia—would pre­sum­ably re­sult in her­i­ta­ble changes. So it’s pos­si­ble to imag­ine a fu­ture in which there are pow­er­ful med­i­cal weapons that would be pro­hib­ited in the U.S.

It’s true that th­ese ad­vances raise eth­i­cal and so­cial con­cerns. In the case of MRT, off­spring would have genes from three peo­ple—nu­clear genes from the main par­ents and mi­to­chon­drial genes from a sep­a­rate “mother.” And the changes this would bring about, how­ever ben­e­fi­cial, would be ir­re­versible.

The way to deal with th­ese con­cerns isn’t to ban the prac­tice. It’s to care­fully mon­i­tor it. Sci­en­tists should pro­ceed with cau­tion—but they should be al­lowed to pro­ceed.

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