Menkes disease is a genetic disorder. A baby is born with it. About 2 in 3 people with Menkes disease have inherited a faulty gene passed down by their birth mother. The other 1 in 3 cases result from new mutations (changes) in their ATP7A gene. The gene that causes Menkes disease, called ATP7A, affects your body’s ability to make a protein that controls amounts of copper in your body. When your ATP7A gene doesn’t work as it should, your body can’t transport copper correctly. People assigned male at birth (AMAB) are much more likely to inherit the gene than people assigned female at birth (AFAB). Menkes syndrome is an X-linked genetic disorder. That means the gene is associated with the X-chromosome. Since people AMAB only have one X-chromosome, they only need one faulty gene to inherit Menkes disease. People AFAB have two X-chromosomes, so they need to inherit two faulty genes for the disorder to occur.