Teenage 'baby' may lack master ageing gene

Pioneering investigations have thrown the first scientific light on the highly unusual case of Brooke Greenberg, a child from Baltimore, Maryland, who is 16 years old, but whose size and development corresponds to that of an infant of 11 months.

Her brain, for example, is scarcely more mature than that of a newborn infant. Although she can recognise her mother and make gestures and noises to articulate her wishes, she can't talk.