Oh, I had something like that too ! Though I reckon it’s less genetics and more randomness/happen-stance: both of my upper milk incisors would not drop on their own. So my “real” incisors decided to take matters in their own hands.
The right one simply pushed the milk tooth out and took its place in time.The left incisor however couldn’t and was forced to push outwards, right through the gum. At one time, I had two teeth one on top of the other. Freaky looking.
Then the lower tooth popped out, but for some reason the “real” tooth didn’t adjust to environmental changes. So to this day I have one apparently enlarged canine that props further forward and downwards than it should. It often pops out when I smile. I tell small children I’m Dhampyr.
The middle and ring fingers of my left hand are distinctly crooked - even the nail of the middle finger grows in crooked. It’s not a huge amount. It’s noticeable, if I point it out, but most of the time people don’t notice. If I lay my hand flat on the table, though, you see it immediately.
Maybe I’ll take a pic and post it - I always thought it was neat. Doctor says it’s because of the way my hands were clasped in the womb.
I also am completely incapable of extending either of my ring fingers without holding all of the other fingers down, and, even held down, the ring finger is not totally flat unless I press it against the table. The ligaments are all bound too tightly.
Everyone else in my family has their second toe roughly about the same size as their big toe and i’ve seen loads of other people like that. I guess i just took notice because mine were different. My mom has TINY feet and i’m always joking with her about it. We went to look for shoes for her and she found some in the boys department haha 
She’s about 5’ 6" and has about a size 4.5 or so.
Situs Ambiguous, which I only found out about when I came around in hospital after being rushed in for an emergency appendectomy.
Being told that “we will have to go in again as we couldn’t find your appendix” is not a good way to build trust in a surgeon.
On the other hand, I have had two appendectomies!
Man, reading this thread leads me to believe that it’s a miracle that most people DON’T have problems with wandering or missing teeth!
What a bunch of freaks you are! 
This thread makes me wonder why marrying first cousins is illegal… How much worse can it get? (Just joking… I know)
Anyway, this has been an interesting thread. “Mother nature’s a MAD scientist!” - Kramer
What, for example IS "a simian crease on a left (or right) palm?
OK, my turn. Not much. But I am somewhat of an expert on the photic sneeze. My father has it, mother doesn’t. My brothers and I all have it to some degree or another, so when we would go to a movie together, mom would have to stand there while everyone around her sneezed like crazy. Talk about a strange spectacle. The best part is that it must be a very dominant gene in our family, because every child born to my brothers and me all have it too.
What a freak show we are when we are all together.
A simian crease is the old-fashioned but still used term for a single transverse palmar crease. It’s when there’s a single line on your palm that goes all the way from one end to another. It’s when instead of two lines (the head and heart lines of palmistry), there’s one. It can be a sign of Down’s Syndrome, or it can just be “one of those things”.
“They” don’t like the term simian crease anymore, because “simian” means “monkey” or “monkey-like”. Some monkeys do, in fact, have simian creases as their norm, but it’s considered poor form to compare people’s babies to monkeys these days, especially if they’re differently abled. 
My dentist discovered many years ago that the nerves in my lower jaw are especially deep – makes it more difficult to fully numb for dental work.
My husband has no wisdom teeth. Neither does our younger daughter. The older did, until she had to have them extracted because they were causing problems.
My right leg was twisted to the right so that the foot pointed out at an angle. They corrected this with special shoes, so now both my feet point straight ahead. My right knee, however, points inward.
The preferred term for “Simian crease” is now “Single palmar crease” in case you were wondering.
I am one of only two people I have ever encountered with simian lines on BOTH palms.
I always thought when I found her, we would be destined for each other, but it was not to be.
I have six also. Do you know why they gave you 4-F - does it cause problems?
Ain’t that the truth. My sister told me when I was a teenager, “Your legs would be fat if they weren’t so long.” Uh, thanks, I guess?
Awww. 
One of my molars grew in forward instead of upward. Also my left lateral incisor grew in small and gimpy and vaguely reminiscent of the Matterhorn.
When I raise just one eyebrow and leave the other one down, it looks completely different from when I do the reverse. For instance, when I raise my right eyebrow and leave the left one down I look serious or inquisitive. When I raise the left one and leave the right one down I look like I’m trying to give a comical-worried look. I can only one the one look with each of the eyebrows.
I’m another one with crooked pinky fingers. Both my daughters, but not my son, have them, the younger moreso than the elder. Apparently, I also have large ‘cups’ (the place where the optic nerve enters the retina) in my eyes. This can be indicative of glaucoma, but all my other eye tests come out normal, and my older daughter has them, too. Obviously, no one but my opthalmologist ever notices them!
As I recall, it introduced enough extra curvature in the spine to give me an “unstable back situation.” Not conducive to humping 60lb packs around, I suppose.
It has caused me problems, especially after my growth spurt at 15. However, posture and working on core muscles have kept it under control.
Yeah, my son had an extra vertebrae and a half (called a demi-vertebrae in orthopedic parlance, apparently) when he was born. The demi-vertebrae had a rib on one side but not the other. Gave him a hell of a scoliosis. The removed the rib and demi during a spinal fusion surgery where they also corrected the scoliosis (mostly).
Which is a shame, because he really wants to go into the military and he’d be really good at it. But even if he didn’t have all the hardware in there, they’d still exclude him for the remaining extra vertebrae, he was told.
I had three wisdom teeth, and no adult canine teeth. My son makes up for the canine loss with huge, pointy ones, so much that he’s been called a vampire by random strangers. However the deep tan and surfer hair tend to pacify them enough that no one’s tried to stake him yet.
I also have the double urethra, one that’s a dead end, the other functional. Didn’t realize it until a nurse tried to cath the wrong one.
I pick things up with my toes all the time. I don’t think it’s actually all that rare in humans, I’ve seen other people do it too. It was probably more common before shoe-wearing became the norm.
I have all my wisdom teeth. They grew in, there was enough room for them, I use them to chew. I’m happy to have them.
I can do most of the things shown on that hypermobility page, though my hypermobility isn’t as extreme as some of those folks.
I’m another guy with a double urethra. And I also thought this was normal. I know my dad is the same way. I don’t know about my brother or any other relatives, and there’s no way I’m asking them about it 
PS: I think both my tubes work, but I’m not 100% sure.
I also have hypermobile hands (looking at the pics on wiki, I can do all of the hand stuff, and I can also bend all my fingers behind other fingers).
I was born significantly pigeon toed, had to wear a brace for a while. The brace was a simple metal rod that connected my shoes together and pointed my feet the correct way. I find when I’m really tired, I walk pigeon toed.
Also, my pinkie toes curled under my fourth toes. When I was 7, I had to spend the entire summer taping my pinkie toes away from their neighbor. It worked, but the curl of my pinkie toes is enough where unless I straighten my foot, you cannot tell I have pinky toenails.
Aanndd, I can easily pick up pretty much anything with my toes.
I didn’t have any teeth until I was over a year old. On the plus side, my dentist has said my teeth are very strong.
My left ear has a weird birthmark - it has a bump near the top, very obvious. I briefly pierced it, but it looked too odd, so I let it close. The family makes drunk Klingon / elf jokes at my expense about it.