Subject: The role of genetics in the developement and ossification of a bone

what role do genetics have in the "timing" of ossification, that is, the age
during which ossification occurs, and in the secretion (and the timing of the
secretion) of the hormones that make bones ossify, such as estrogens?
For istance: if my father continued to grow till 21 years of age, and my uncles
(my mother's brothers) continued till about 18, is it likely that my bones will
not ossify until 18 or 21 years of age?
Thanks 

Re: The role of genetics in the developement and ossification of a bone