Can it be Genetic?

Kellan will be 15 months old on Saturday. He is still not walking. I believe wholeheartedly that he will walk next month. Why? Well, not only because its about time, but also because there seems to be a family history of children starting to walk at 15 months of age. I wouldn't have believed that something like this could be genetic, but its hard to explain away. 15 months is very late for walking, especially since Kellan has been on his feet for a couple of months already, doing nothing but walking (with parental aid) everywhere that we go. He can stand on his own. There is no logical reason to explain his inability to walk. Yet, he can't (or won't). I walked at 15 months. Many of my cousins and their children walked at 15 months. So, for whatever reason, I believe that Kellan will also walk at 15 months. Fingers crossed and back aching, I hope to report back soon with the happy news that we have a toddler in the house.