Alexandria's Genesis Is Not Real
A lot of people have asked whether or not this is true, and the short answer is... no.
The long answer is that Alexandria's Genesis was created around the turn of this century by a novice writer to justify the existence of perfect purple-eyed people in her fanfiction. The creator never intended it to be taken as actual fact (or even an actual myth), but a few gullible starry-eyed folks mistook it for such and started spreading it around the Internet. Today, there are people convinced that Alexandria's Genesis really exists and that everyone who says otherwise is closed-minded or a shill for The Conspiracy.
The original creator has created a page to to address and dispel the myth of Alexandria's Genesis here (at least at the time of this writing - the blog has changed locations several times before). In the event that the page vanishes or you want a more biologically-oriented explanation of why it's impossible, here's my own breakdown of why Alexandria's Genesis is not only nonexistent, but also impossible.
First things first: the traits of Alexandria's Genesis are said to have arisen through a mutation. However, there is no way a single mutation could affect that many aspects of the human body, let alone in such a positive manner. All of the areas said to be affected by Alexandria's Genesis are in reality controlled by many different genes.
Now, let's examine the traits and their plausibility:
Violet eyes: Technically possible through a severe lack of eye pigmentation (eg, albinism). However, eyes colored thus are extremely sensitive to sunlight - a trait that wouldn't be very pleasant to have in sunny Egypt! To have purple eyes without being sensitive, you'd need a whole new color of pigmentation altogether, possibly a reddish color.
No body hair: Plausible, sort of. Androgen insensitivity syndrome can result in a lack of body and facial hair, but it only happens in people carrying both Y and X chromosomes. While those who have AIS can have outwardly biologically-female bodies, they cannot bear children as they lack uteri. This completely contradicts the notion that people with Alexandria's Genesis are supposed to be fertile. Otherwise, to get the particular effect Alexandria's Genesis is said to have, many generations of breeding would be required. (Some people and ethnic groups do have very little body hair, but this has nothing to do with Alexandria's Genesis.)
The mutation passes down to children, and gets stronger every generation: Since the mutation is supposed to date back to ancient Egypt, if it really behaved in the manner described there would be very few people without Alexandria's Genesis in the world today. Mathematically, anyone who lived in ancient Egypt and has descendants now would be a common ancestor to all people living now. The nigh-invulnerable immune system that comes with Alexandria's Genesis would mean that those who had it would survive diseases that decimated those without it, further ensuring that the condition would be spread around. If it were real, it would be impossible for the government to cover up (as some have claimed), because just about every person you know would have it.
No periods, yet still fertile: Not biologically impossible, as many animals undergo an estrous cycle where the lining of the uterus is reabsorbed rather than expelled. However, this would require a lot of genetic modification for to change - a single mutation wouldn't do it.
Their metabolism burns everything efficiently, so they produce little to no waste and never become overweight: If all of these statements are true, those with Alexandria's Genesis would have a ridiculously high body temperature. (The energy produced by burning all of those calories has to go somewhere.) It would be like they were constantly running a fever, which would result in a dangerously high risk of overheating - not much fun in balmy Egypt!
Pale, burn-resistant skin with a metallic sheen: ...Is this where the heavy metals that aren't building up in their organs and killing them because they don't actually poo are going? Are these metals somehow responsible for their sun-resistant porcelain skin? Some invertebrates (eg, spiders and beetles) have metallic shells or metallic shells on their spots, and birds can have shiny feathers, so it's not biologically implausible that you could have someone with a shimmery skin, but again, this is one of those things that would require far more than a single mutation to accomplish.
Perfectly-proportioned bodies: What does this even mean? The closest you can objectively get to "perfectly proportioned" in the human body is "as symmetrical as possible." Otherwise, differing beauty standards and whatnot mean that different features will be found differently attractive depending on where and who you ask.
Long lifespans and perfect eyesight: Not impossible, but in light of everything else, it's safe to conclude that Alexandria's Genesis does not and cannot exist.
TL;DR: Alexandria's Genesis could only be a real mutation in a world like that of The Uncanny X-Men. In the real world, it's impossible as described per Cameron Miquelon's original specifications.
Here are some other pages you might want to check out:
Tips To Identify Hoaxes & Urban Legends
Not All Myths & Legends Are Based In Truth
A Beginner's Guide To Spotting Cranky Websites
Things Science Fiction & Fantasy Writers Should Know About Science
Tips to Create Better & More Believable Fantasy & Science Fiction Species
Things To Know If Your Character Will Be Augmented Or Experimented Upon
Go to a random page!