For patients:

Inclusion Criteria:

• Girls aged 6 to 8 years
• Presenting a breast development (isolated or not)
• Undergoing scheduled pediatric day hospital care (HDJ)
• Who agree to participate in the study
• Whose parents agree to their child's participation in the study
• French speaking
• Whose parents speak French
• Affiliated to social security

Exclusion Criteria:

• Organic brain causes of precocious puberty: History of neurocerebral disease (malformations, developmental abnormalities)
• Organic causes of precocious puberty: Mac Cune Albright syndrome, ovarian cyst or tumor and adrenal hyperplasia
• History of chemotherapy or radiation therapy
• Presenting with a communication disorder
• Pregnancy
• Persons under protective measures
• Persons deprived of liberty for judicial or administrative reasons

For controls:

Inclusion Criteria:

• Girls aged 6 to 8
• Tanner stage 1: Absence of breasts and hairiness
• Coming for routine consultation in the pediatric HDJ at Saint-Vincent-de-Paul hospital, or at the BLM practice in Lambersart, or to radiology for an MRI for another medical other medical reason
• Agree to participate in the study
• Whose parents agree to their child's participation in the the study
• French-speaking
• Whose parents speak French
• Affiliated with social security

Exclusion Criteria:

• Signs of puberty (Tanner stages 2, 3, 4 and 5 for breast development) breast development)
• Previous chemotherapy or radiotherapy
• Presenting a communication disorder
• Pregnant women
• Persons under protective supervision
• Persons deprived of their liberty for judicial or administrative reasons