Unlike vampires and zombies, werewolves can actually be born into their "condition". In order for this to happen though, the "werewolf gene" must be present in both parents.
It's not as simple as you might think. Surprisingly, the werewolf gene is a recessive gene, meaning that when it is paired with the dominant human gene, it remains "inactive". This, of course, is a huge simplification of the entire genetic process, but it's all you really need to know to understand how to become a werewolf by birth.
Everyone's chromosomes come in pairs. You get one chromosome from your
father and one from your mother. The paired chromosome that you end up
with is a combination of those two. Since your parents also have a pair
of each chromosome, you will only get one of the two
chromosomes that they carry.
What this means is that your pair of chromosomes will be a random combination of one of the two chromosomes your father carries and one of the two chromosomes your mother carries.
The chart below will hopefully shed some light on this explanation.
I know it probably seems confusing if this is your first foray into genetics, but this is essentially the only real explanation necessary to describe how the gene works.
As you can see from the chart, a combination of "HH" (Human/Human), "Hw" (Human/werewolf), or "wH" (werewolf/Human), all result in the same thing - a human child. This means that because the Human Gene is dominant over the Werewolf Gene, the resulting child will be born as a regular human.
Only in the instances where the combination of chromosomes results in a "ww" (werewolf/werewolf) combination will the child be born a werewolf.
As you can tell from the chart above, most combinations of human and werewolf genes will result in a human child. That doesn't mean that the werewolf gene does not exist in that child. It certainly does. "Hw" and "wH" combinations may be dominated by the human gene, but the werewolf gene is still a part of the parent's genetic structure.
Let's draw up an example:
Say a human marries a werewolf. Let's use Combo #7 for this. The father is full-on "ww" werewolf and the mother is full-on "HH" human. The resulting child will certainly be a "wH" human. From the outside, this child will seem like a normal human being, never transforming into a werewolf by the light of the moon.
Let's go one step further. Say this child, our "wH", reproduces with another human with a recessive werewolf gene. Let's use Combo #5 for this (the order of the genes doesn't matter - "wH" is the same as "Hw"). Our child is the father, having "Hw", and the mother is the same, an "Hw". The resulting child of this pair has a 25% chance of being a werewolf, despite having two human parents!
The last thing I will mention is that when talking about any genetic structure, there are always random mutations that occur. In werewolves, one particular mutation causes a fascinating condition called Human Werewolf Syndrome.
Read about Human Werewolf Syndrome or return to the main Werewolves page.