| Phenotype Category | Specific Clinical Feature | Age of Onset | Gender Predominance | Frequency (if available) | HPO Term Suggestion |
|---|---|---|---|---|---|
| Secondary Sexual Characteristics | Progressive breast development (thelarche) before age 8 years, following the normal pubertal sequence | Childhood; typically <8 years in girls | Predominantly girls | Core defining feature in girls with CPP; exact frequency not stated in gathered sources (pqac-00000001, pqac-00000008, pqac-00000014) | HP:0000978 Breast development premature |
| Secondary Sexual Characteristics | Testicular enlargement >4 mL before age 9 years | Childhood; typically <9 years in boys | Boys | Core defining feature in boys with CPP; exact frequency not stated in gathered sources (pqac-00000001, pqac-00000014, pqac-00000015) | HP:0000047 Precocious puberty, male |
| Secondary Sexual Characteristics | Progressive pubertal features/secondary sexual characteristics appearing earlier than expected for age | Childhood | Strong female predominance overall; CPP prevalence 5-10 times higher in girls than boys (pqac-00000009) | Common presenting manifestation; sex disparity noted, not phenotype-specific frequency (pqac-00000007, pqac-00000009, pqac-00000014) | HP:0000826 Precocious puberty |
| Growth Parameters | Accelerated linear growth / pubertal growth spurt | Childhood, concurrent with pubertal activation | Both sexes | Common characteristic of CPP; treatment-naive patients in one trial had mean height velocity decline from 10.1 to 6.5 cm/year after therapy, supporting increased pretreatment growth velocity (pqac-00000007) | HP:0001548 Growth acceleration |
| Growth Parameters | Advanced bone age relative to chronological age | Childhood, usually at presentation | Both sexes | Frequently present; diagnostic descriptions often require bone age advancement, and one cohort required bone age advanced by at least 1 year (pqac-00000009); reviews note typically advanced, sometimes by >=2 years (pqac-00000014) | HP:0002750 Advanced skeletal maturation |
| Growth Parameters | Early epiphyseal maturation with risk of premature cessation of linear growth and reduced adult height | Childhood to adolescence | Both sexes | Important complication rather than universal presenting sign; repeatedly emphasized in reviews and treatment studies (pqac-00000007, pqac-00000014, pqac-00000015) | HP:0003510 Short adult stature |
| Hormonal Changes | Premature activation of the hypothalamic-pituitary-gonadal axis with pulsatile GnRH secretion | Childhood | Both sexes | Pathophysiologic hallmark of CPP (pqac-00000001, pqac-00000002, pqac-00000014) | HP:0000826 Precocious puberty |
| Hormonal Changes | Pubertal LH response on GnRH/GnRH-agonist stimulation testing | Childhood, at diagnosis | Both sexes | Core biochemical diagnostic finding; one biomarker study used peak LH >=6 IU/L to define CPP vs <6 IU/L for PT (pqac-00000008); another study required elevated gonadotropins and positive LHRH provocation test (pqac-00000009) | HP:0031066 Increased circulating luteinizing hormone level |
| Hormonal Changes | Elevated basal or stimulated gonadotropins (LH, FSH) | Childhood | Both sexes | Common laboratory abnormality used diagnostically; exact prevalence not stated (pqac-00000014, pqac-00000015) | HP:0031066 Increased circulating luteinizing hormone level |
| Hormonal Changes | Detectable pubertal estradiol exposure in girls | Childhood | Girls | Common in CPP, though estradiol may be less diagnostically useful than LH; one treatment study used estradiol <20 pg/mL as suppression target (pqac-00000007, pqac-00000014) | HP:0030358 Increased circulating estradiol level |
| Hormonal Changes | Elevated testosterone in boys with central puberty | Childhood | Boys | Useful marker in boys, though does not distinguish central from peripheral causes by itself (pqac-00000014) | HP:0030348 Increased circulating testosterone level |
| Diagnostic/Imaging Correlate | Normal brain MRI in idiopathic CPP; absence of structural lesion after exclusion of organic causes | Childhood, during diagnostic workup | More often idiopathic in girls; boys more likely to have organic etiology | Idiopathic CPP especially common in girls; MRI used to exclude lesions (pqac-00000006, pqac-00000014, pqac-00000015) | HP:0012444 Abnormal hypothalamic-pituitary imaging excluded in idiopathic cases |
| Metabolic Features | Overweight/obesity association | Often present in childhood; may precede or accompany CPP | More documented in girls | Association repeatedly reported, especially in girls; exact phenotype frequency not provided (pqac-00000000, pqac-00000005) | HP:0001513 Obesity |
| Metabolic Features | Increased long-term risk of obesity, type 2 diabetes, and cardiovascular disease | Long-term outcome after childhood CPP | Both sexes, evidence emphasized in girls | Reported as recognized long-term complications rather than baseline phenotype frequencies (pqac-00000002, pqac-00000009, pqac-00000014) | HP:0001513 Obesity / HP:0005978 Type 2 diabetes mellitus |
| Metabolic Features | Familial DLK1-related CPP may coexist with metabolic abnormalities such as hyperlipidemia, overweight, or hyperuricemia | Childhood/adulthood in rare genetic forms | Both sexes in affected families | Rare, genotype-specific manifestation (pqac-00000006, pqac-00000010, pqac-00000015) | HP:0003124 Hypercholesterolemia / HP:0002149 Hyperuricemia |
| Psychosocial / Quality of Life | Psychosocial distress associated with early pubertal development | Childhood to adolescence | More studied in girls | Recognized complication; exact frequency not available in gathered texts (pqac-00000002, pqac-00000014) | HP:0012735 Emotional lability |
| Treatment Response Phenotype | Suppression or stabilization of pubertal signs after GnRH agonist treatment | During treatment | Both sexes | In a phase 3 trial, physical signs were suppressed at week 48 in 90.2% of girls and 75.0% of boys (pqac-00000007) | HP:0000826 Precocious puberty (treated/suppressed phenotype) |


*Table: This table summarizes the main clinical manifestations of central precocious puberty across physical, growth, hormonal, metabolic, and psychosocial domains. It is useful for mapping disease presentation to ontology terms and for distinguishing core diagnostic features from complications and treatment-response phenotypes.*