Rare diseases · Sign or symptom
External genital hypoplasia
Underdevelopment of external reproductive organs
HP:0003241
What it means
Underdevelopment of part or all of the external reproductive organs.
Partial or complete failure of the genitalia to develop, often as a consequence of hypogonadism.
Rare diseases that can present with this32
Very common80–99%
7Common30–79%
13- Colobomatous microphthalmia-obesity-hypogenitalism-intellectual disability syndrome
- Intellectual disability-balding-patella luxation-acromicria syndrome
- MOGS-CDG
- Neu-Laxova syndrome
- Prader-Willi syndrome
- Prader-Willi syndrome due to maternal uniparental disomy of chromosome 15
- Prader-Willi syndrome due to paternal 15q11q13 deletion
- Prader-Willi syndrome due to paternal deletion of 15q11q13 type 1
- Prader-Willi syndrome due to paternal deletion of 15q11q13 type 2
- Prader-Willi syndrome due to translocation
- Robinow syndrome
- Schaaf-Yang syndrome
- SIM1-related Prader-Willi-like syndrome
Sometimes5–29%
11- 6q25.2q25.3microdeletion syndrome
- 9p13microdeletion syndrome
- Congenital muscular dystrophy with intellectual disability and severe epilepsy
- DPM1-CDG
- Hereditary bullous dystrophy, macular type
- Kagami-Ogata syndrome due to paternal uniparental disomy of chromosome 14
- Lenz-Majewski hyperostotic dysplasia
- Myhre syndrome
and 3 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: Hypogenitalism · Small genitalia
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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.