aromatase excess syndrome
Findings
No curated finding names aromatase excess syndrome yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Aromatase excess syndrome is 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.
Definition from the Mondo Disease Ontology (MONDO:0007690), read 2026-09-29. CC BY 4.0.
Features
18 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Elevated aromatase activityHPOHP:0034699
- Very frequent (80% to 99% of cases)
- GynecomastiaHPOHP:0000771
- Very frequent (80% to 99% of cases)
- Increased serum estroneHPOHP:0025139
- Very frequent (80% to 99% of cases)
- Accelerated skeletal maturationHPOHP:0005616
- Frequent (30% to 79% of cases)
- Decreased circulating follicle stimulating hormone concentrationHPOHP:0030341
- Frequent (30% to 79% of cases)
- Hypogonadotropic hypogonadismHPOHP:0000044
- Frequent (30% to 79% of cases)
Show the remaining 6
- Enlarged uterusHPOHP:0100878
- Occasional (5% to 29% of cases)
- Irregular menstruationHPOHP:0000858
- Occasional (5% to 29% of cases)
- Male hypogonadismHPOHP:0000026
- Occasional (5% to 29% of cases)
- Mild short statureHPOHP:0003502
- Occasional (5% to 29% of cases)
- Precocious puberty in femalesHPOHP:0010465
- Occasional (5% to 29% of cases)
- Premature thelarcheHPOHP:0010314
- Occasional (5% to 29% of cases)
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- CYP19A1HGNC:2594
- Moderate · Ambry Genetics · Autosomal dominant · 2024
- Supportive · Orphanet · Autosomal dominant · 2021
- Limited · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2017
Where it sits
Other names
5 names
Resolves to: aromatase excess syndrome
- Also called
- AEXSfamilial hyperestrogenismgynecomastia, familial, due to increased aromatase activitygynecomastia, hereditaryhereditary prepubertal gynecomastia