MKRN3 and precocious puberty: Central precocious puberty is clinically defined as the presence of secondary sexual characteristics before the age of 8 years in girls and 9 years in boys.38 About half of all cases of familial central precocious puberty carry a mutated paternal copy of MKRN3, a PEG from the PWS/AS region of chromosome 15.38 Furthermore, most children with uniparental maternal disomy of chromosome 14, known as Temple syndrome, or TS14, undergo precocious puberty.39DLK1 is included in a cluster of imprinted genes on chromosome 14 (Fig 4).