Ricki Lewis

One of my greatest joys in revising my human genetics textbook is adding treatments for genetic diseases that have been FDA-approved since the last edition. The list has grown quite a lot since I finished the last revision as the pandemic finally faded away, and certainly since my gene therapy book was published in 2013. And so I was thrilled a few days ago when the father of a boy who had Menkes disease reposted my DNA Science blog from 2021, which described the rare disease, the clinical trial, and the family's participation.

The "new" treatment – many kids with Menkes have been part of the clinical trial for years – is a simple injection administered daily under the skin that delivers copper, which the body cannot process from food. It's not gene therapy, nor gene editing, nor magic – it is a sensible, decades-old strategy of finding a way around a biochemical glitch. Specifically, the drug Zycubo, aka copper histidinate, is a copper replacement therapy. Cyprium Therapeutics developed the long-awaited treatment.

To continue reading, go to DNA Science, where this post first appeared.

Headlines often trumpet the latest in gene editing, RNA drugs, or gene therapy. The less buzzy, but more classic strategy of providing a nutrient that a genetic glitch blocks, has been quietly making strides against Menkes disease, which impairs copper absorption. November is Menkes disease awareness month.

Copper Deficiency

Menkes disease results from a mutation in a gene (ATP7A) on the X chromosome, so its affects boys. About 70% inherit the mutation from their mothers, who are carriers. The rest have a new mutation that arises in egg or sperm.

The healthy version of the gene encodes a protein that controls enzymes that shuttle copper from food through the lining of the small intestine into the bloodstream, and into the brain, where copper is vital for neural connectivity. The mineral is also essential for hair growth and pigmentation, which is why Menkes is also called kinky hair disease. Boys have sparse, pale, and twisty hairs.

Aside from the unusual hair, the child seems healthy until about 3 months. Then symptoms become increasingly noticeable: poor growth, developmental delay, seizures, weak muscles, and low body temperature. Many boys die before their third birthdays.

To continue reading, please go to my DNA Science blog at Public Library of Science, where this post first appeared.