"It looks like we have found a key genetic gatekeeper of puberty in mice and men, " said Dr William Crowley Jr, chief of the reproductive endocrine unit and one of those involved in the study.

BBC: NEWS | Health | Gene 'decides timing of puberty'

"They have a well-oiled machine, " said Patrick, one of the authors of the national study, said of the Knoxville hospital unit.

NPR: Tenn. Hospital Treats Drug-Dependent Babies