Rare diseases · Sign or symptom
Precocious puberty
Early onset of puberty
HP:0000826
What it means
The onset of secondary sexual characteristics before a normal age. Although it is difficult to define normal age ranges because of the marked variation with which puberty begins in normal children, precocious puberty can be defined as the onset of puberty before the age of 8 years in girls or 9 years in boys.
Rare diseases that can present with this60
Very common80–99%
6Common30–79%
4Sometimes5–29%
33- 19p13.12microdeletion syndrome
- 19p13.3microduplication syndrome
- 8p inverted duplication/deletion syndrome
- 9p13microdeletion syndrome
- Aicardi syndrome
- Alexander disease
- CNTNAP2-related developmental and epileptic encephalopathy
- Dystonia 28
and 25 more in this range
Rare1–4%
17- 17q11microdeletion syndrome
- Carney complex
- Early infantile developmental and epileptic encephalopathy
- Epilepsy of infancy with migrating focal seizures
- Inverted duplicated chromosome 15 syndrome
- Kleefstra syndrome due to a point mutation
- Peripheral primitive neuroectodermal tumor
- Phakomatosis pigmentokeratotica
and 9 more in this range
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Early puberty
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.