Can narcissistic personality disorder have roots in a childs upbringing?

Absolutely. There are subtypes of narcissistic personality, but in general you will find self-importance and grandiosity masking feelings of emptiness and inferiority. In other words, somewhere in the early years, a parent was insufficiently attuned to the child's emotional needs.
Yes. Current thought is that all personality disorders start in childhood and are a result of how the child adjusts to his environment. This is partially due to genetics, what tendencies are inherited, and partially to how the environment and those in it respond to the child.