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ORPHA:178345

Aromatase excess syndrome

low confidenceDisorder

Also known as: AEXS · Familial hyperestrogenism · Hereditary prepubertal gynecomastia

Query health: suspect — Only one of 2 strategies returned hits (phrase).

Publications

8,934

Trials

0

Interventional, condition-specific

Researchers

519

Distinct authors in sample

Gene link

CYP19A1

Moderate

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare, genetic endocrine disease characterized by increased levels of estrogen due to elevated extraglandular aromatase activity. Males present with heterosexual precocious puberty which manifests with pre- or peripubertal onset of gynecomastia, premature growth spurt, accelerated bone maturation resulting in decreased adult stature, and may present mild hypogonadotropic hypogonadism. Female patients may have isosexual precocious puberty or not have any manifestations at all.

How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (5)

aromatase excess syndrome · familial hyperestrogenism · gynecomastia, familial, due to increased aromatase activity · gynecomastia, hereditary · hereditary prepubertal gynecomastia

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

4/6 stages with a signal

No matched interventional trial, but a gene association and an animal model are on record — often described as translation-ready / stalled at the clinical step.

  1. Gene identifiedPresent

    Moderate — CYP19A1

  2. LiteraturePresent

    8,934 matched papers (6,660 in last 10 years) Source

  3. Phenotype characterisedPresent

    21 HPO annotations (e.g. Breast hypertrophy; Precocious puberty in females; Accelerated skeletal maturation) Source

  4. Animal modelPresent

    1 genotype model (Mus musculus) Source

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialNot found

    No matched interventional trial under our ClinicalTrials.gov rules

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Probably — there is moderate evidence for CYP19A1.

GenCC classification: Moderate.

Phenotypes (Monarch / HPO)

21

Associated phenotypes · MONDO:0007690

  • Breast hypertrophy
  • Precocious puberty in females
  • Accelerated skeletal maturation
  • Gynecomastia
  • Increased serum estrone

Showing 5 of 21 — open Monarch for the full list.

Animal models (Monarch / Alliance)

1

Model associations linked to this Mondo ID

Monarch fetch 2026-07-29

Therapies

Designations, candidates, and chemicals

FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.

Orphan designation (FDA · EMA)

No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.

Open Targets candidates

No drugs or clinical candidates returned for this Mondo ID on Open Targets.

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

8,934

8,934 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

8,934 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).

6,660 in the last 10 years · low confidence

Phrase hits: 110 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

519

Distinct author names in 110 sampled papers — named people below.

Who's working on it?

No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.

  1. 01
    Fukami M14 papers · 2026

    Department of Molecular Endocrinology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo, 157-8535, Japan, fukami-m@ncchd.go.jp.

    Papers in Europe PMC
  2. 02
    Ogata T11 papers · 2022

    Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu, Japan

    Papers in Europe PMC
  3. 03
    Shozu M9 papers · 2014

    Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan

    Papers in Europe PMC
  4. 04
    Binder G4 papers · 2021

    Pediatric Endocrinology Section, University-Children's Hospital, Hoppe-Seyler-Str.1, 72076 Tuebingen, Germany. gdbinder@med.uni-tuebingen.de

    Papers in Europe PMC
  5. 05
    Nagasaki K4 papers · 2021

    Division of Pediatrics, Niigata University Graduate School of Medicine and Dental Science, Niigata, Japan.

    Papers in Europe PMC
  6. 06
    Bulun SE3 papers · 2013

    Division of Reproductive Biology Research, Department of Obstetric and Gynecology, Northwestern University, Chicago, IL 60611, USA. s-bulun@northwestern.edu

    Papers in Europe PMC
  7. 07
    Li X3 papers · 2022

    Department of General Surgery, The 301th Hospital of PLA, Beijing, China.

    Papers in Europe PMC
  8. 08
    Martin RM3 papers · 2008

    Unidade de Endocrinologia do Desenvolvimento, Laboratório de Hormônios e Genética Molecular LIM/42, Divisão de Endocrinologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, 01065-970 São Paulo, Brasil. reginamm@usp.br

    Papers in Europe PMC
  9. 09
    Miyado M3 papers · 2017

    Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan.

    Papers in Europe PMC
  10. 10
    Nakabayashi K3 papers · 2014
    Papers in Europe PMC

Clinical research

Is a treatment being tested?

0

interventional trials for this specific condition

No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present).

Data as of 11 September 2026 · last trial check 11 September 2026

No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.

low confidence · 38.6th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.

See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.

Other registries (secondary)

Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.

raw 0 · after dedupe 0 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · dropped 0 · fetched 2026-07-30

Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri

No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).

Where to find support

Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.

Orphanet entry for Aromatase excess syndrome — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

("Aromatase excess syndrome" OR "Familial hyperestrogenism" OR "Hereditary prepubertal gynecomastia" OR "gynecomastia, familial, due to increased aromatase activity" OR "gynecomastia, hereditary") OR (MESH:"familial gynecomastia, due to increased aromatase activity") OR ("CYP19A1" OR "CYP19A1 syndrome" OR "CYP19A1-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: familial gynecomastia, due to increased aromatase activity

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"Aromatase excess syndrome" OR "Familial hyperestrogenism" OR "Hereditary prepubertal gynecomastia" OR "gynecomastia, familial, due to increased aromatase activity" OR "gynecomastia, hereditary" OR "familial gynecomastia, due to increased aromatase activity"

Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.

Query health: suspect — strategies attempted: phrase, mesh; with hits: phrase

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: AEXS

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • 1 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus
  • Publication count (8934) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T08:49:21.413Z