X-linked recessive inheritance

Okay kiddo, let's imagine that you have a toy car that has a secret code written on it. This secret code is like a special instruction that tells your body what to do.

Now, sometimes when you get older and have kids of your own, you might want to pass on this toy car to them. But here's the tricky part - the secret code is only written on the car you have, and you only have one copy of it.

This is kind of like how humans have something called genes, which are like the secret codes for our bodies. But instead of toy cars, our genes are inside our cells and they tell our bodies what color our eyes are, how tall we are, and lots of other things.

Also, some genes are only found on certain chromosomes in our cells. These are like little packages that hold a bunch of genes together.

One important gene that is found on the X chromosome is called "X-linked recessive." And just like your toy car secret code, people can have different versions of this gene.

Now here's where things get a bit complicated. In order for a person to be affected by the X-linked recessive gene, they need to have two copies of it - one on each X chromosome. But since boys only have one X chromosome and girls have two, this means that boys are more likely to be affected by the X-linked recessive gene.

For example, imagine that your mommy is a carrier of the X-linked recessive gene. This means that she has one copy of the gene, but she doesn't have any symptoms because she also has a normal copy of the gene on her other X chromosome.

But if your daddy doesn't have the X-linked recessive gene at all, then you won't be affected because you also have a normal copy of the gene on your other X chromosome.

However, if you were a boy and your mommy was a carrier, then you would only have one X chromosome (from your mommy) and you would have a 50% chance of inheriting the X-linked recessive gene. If you did inherit it, then you would have symptoms of whatever condition the gene causes, because you don't have a normal copy of the gene on your other X chromosome to balance it out.

So basically, X-linked recessive inheritance is when a gene called X-linked recessive is only found on the X chromosome and affects boys more than girls. It can be passed down from a mommy who is a carrier and affects boys who inherit the gene on their one X chromosome.