GNRH1 and central precocious puberty: A variant of precocious sexual maturation in girls with intermediate clinical features between IPT and CPP. Breast development without pubic or axillary hair and accelerated growth velocities or advanced bone age. Pelvic ultrasound assessment shows ovaries and uteri intermediate between those of premature thelarche and precocious puberty. At LHRH test: values of FSH higher than LH, with no significant gonadotropin pulsatility. Treatment with LHRHa does not decrease breast development.