Genetic and environmental factors combine to create something called clubfoot, where one of the feet or both are rotated inward and downward on newborn children. The foot and leg may also be smaller than is normal, but various treatments are available to correct the issues. These include casting, manipulation of the Achilles tendon, braces, and surgery.
Without this help walking can be painful and difficult, though as long as it’s treated with time, people who have developed clubfoot usually have no issues in life other than an interesting fact about themselves. It’s more common, for some reason, in first children as well as males.
Sneezing in the Sun
A number of humans have something called the photic sneeze reflex – there's a reasonable chance you have it since it affects a quarter of the population. If you've ever sneezed when you step into bright sunlight, then you have it.
Scientists are, to put it mildly, baffled about why this happens. However, it's clear it's genetic – if one of your parents has it, you have a fifty percent chance of also having it. While sneezing isn't really dangerous, having a weakness for bright lights during driving or operations can pose some interesting problems.
No Colors Here
Color blindness – or color vision deficiency – is the decreased ability to see color or differences in color. There are several versions, including total color blindness where the sufferer only sees in shades of gray. The most common cause of this disorder is a genetic problem in the development of the eyes' cone cells, which sense color.
Since the genes that carry these problems are on the X chromosome, men suffer from this disorder far more than women. The disorder makes people unable to have certain jobs, including pilots, train drivers, and many positions in the armed forces.
Hairless From Head to Toe
It's a sad fact of life that most people will have some hair loss. Even women will lose their mane volume over time. Alopecia Universalis, however, is that turned up to eleven. It's a complete lack of hair on the entire body – head, eyebrows, beard, chest, arms, legs, back, everywhere. However, people who have this disorder are otherwise completely healthy with no other symptoms.
The true cause isn't entirely known, but the current consensus is it's an autoimmune disorder where the body attacks hair follicles. Once again, genetics may also play a part, as twenty percent of people with alopecia Universalis have a family member who is also affected.
You've heard of the condition strabismus before, but you've probably heard of it by the name of being cross-eyed. Whether only sometimes or constantly, people who are cross-eyed have trouble focusing both eyes on one place. It can be the result of muscle dysfunction, farsightedness, problems in the brain, or even infections or trauma. It's also thought to have a genetic factor.
Strabismus occurs in about two percent of children, and there are various treatment types depending on the intensity, including simple glasses or surgery. Related is something called “Wall-eye” where the eyes look away from each other. Both disorders fall under the strabismus umbrella.