Activating GNAS1 gene mutations in patients with premature thelarche.

Objective: To identify GNAS1 gene mutations in girls with exaggerated and/or chronic fluctuating thelarche for at least 1-year duration with no other signs of precocious puberty, skeletal dysplasia, or typical skin lesions of McCune-Albright syndrome.

Study Design: We studied the GNAS1 gene mutation by allele-specific polymerase chain reaction and enzymatic digestion in leukocyte DNA in 23 girls previously described.

Results: Fluctuating thelarche was present in 14 girls and exaggerated thelarche was observed in 9.