Baby is healed with first personalized gene-editing treatment

>KJ has made medical history. The baby, now 9 ½ months old, became the first patient of any age to have a custom gene-editing treatment, according to his doctors.

This is _not_ the first human to be treated with a treatment under the wide umbrella of gene therapy based on their own edited genes. There probably is a more narrow first here but the technical details get lost in journalism which is a shame.

Okay, I'll bite: Who then was the first patient of any age to have a custom gene-editing treatment?

I know of at least one YouTuber who took a homemade treatment that alerted his GI system DNA to produce lactase so he could eat pizza again:

https://youtu.be/J3FcbFqSoQY

That's not gene editing, but you could call it a gene therapy - he's introducing new fragments of DNA/RNA into his cells which then just float around and cause the right enzyme get made. Sometimes called upregulation. This is different to actually editing the existing DNA in the cell.