Brittle bone is a genetically transferred disease from one generation to the next generation through families. It is a genetic disorder where there is no formation of collagen, a soft tissue in the bones that helps to form bones and maintains its strength. When there is no enough collagen in your bones, they become soft and more likely to bend. Sometimes, we can easily break the bones that are in lack collagen. That means the bones become brittle without collagen. Hence, collagen is the primary substance that is damaged in brittle bone.