That's one of the biggest problems with blaming genes. It makes you powerless. You have the ability to get in shape. That doesn't mean you can turn yourself into a perfectly shaped 6'5" Adonis. There are certainly genes that factor into the final product. But you aren't doomed to be fat. Congratulations on your success. Don't stop now! Keep going! You have so much to be proud of and yet still so much to accomplish.