So much hand-waving that I couldn't make up my mind whether to comment... here goes and if you see this, it means I didn't decide to delete my comment and bury this thread from view...

Let's start with two facts that might help put this all in perspective:

1) Genetic engineering of a grown adult is very dangerous, if your delivery mechanism hits the wrong target, if your nuclease / integrase hits the wrong site, if anything at all is peculiar with your therapy, you're liable to mutate the wrong gene and give yourself cancer. Right now, the best of these therapies are still working on the most simple of genetic diseases where we already know the direct effect between a 1 base pair substitution in DNA and the disorder. And even those are still suffering setbacks in the clinic (And guess what, even CRISPR isn't the magic bullet here).

There's plenty of promise in gene therapy, but there's also plenty of danger, and for the near future, it's going to be limited to genetic diseases, of which a low IQ is not one.

2) We really don't understand the brain. We know IQ correlates better with environment than genetics, we know that certain regions of the brain correlate with certain functions, but Alzheimer's? Autism? Grandmother cells? Still mysteries.

Then you try to add into the mix the thousands of SNPs flagged by a GWAS that correlate with IQ (Meaning they could be spurious, nearby another functional mutation, or effect the epigenome in ways we're still just learning how to measure), and you have an idea destined for failure from the start.

But the largest effect size researchers have been able to detect thus far is less than a single point of IQ.

...

Given that there are many thousands of potential positive variants, the implication is clear: If a human being could be engineered to have the positive version of each causal variant, they might exhibit cognitive ability which is roughly 100 standard deviations above average. This corresponds to more than 1,000 IQ points.

Yeah, because those are all guaranteed to be real, causative, and independent, additive effects, and not leave an individual with their neurons wrapped around one another like the most fractally-knotted string you've ever seen.

In twin and adoption studies, pairwise IQ correlations are roughly proportional to the degree of kinship, defined as the fraction of genes shared between the two individuals. Only small differences due to family environment were found: Biologically unrelated siblings raised in the same family have almost zero correlation in cognitive ability. These results are consistent over large studies conducted in a variety of locations, including different countries.

... a tale which gets a lot more muddied when you actually look deeper than the facts that support your argument ...

Want my take on this all? There's a lot of research into teaching that is a lot less cool sounding than genetic engineering of the brain, but has a lot more effect.

(Note: this is not the first Nautilus article I've had serious issues with)