Overview
Testicular agenesis, also known as anorchia or vanishing testes syndrome, is a rare condition in which one or both testicles are completely absent at birth in a person who has male chromosomes (46,XY). The condition is different from undescended testicles, where the testicles exist but have not moved into the scrotum. In testicular agenesis, the testicles either never fully developed or were lost during fetal development, possibly due to a disruption in blood supply (called testicular torsion) while the baby was still in the womb. Because the testicles are responsible for producing testosterone and sperm, their absence can lead to a range of effects depending on when during fetal development the loss occurred. If the testicles were present long enough during early pregnancy to produce hormones, the baby will typically have normal male external genitalia. If the loss happened very early, the genitalia may appear ambiguous or underdeveloped. Key symptoms include an empty scrotum on one or both sides, possible delayed puberty, lack of secondary sexual characteristics such as facial hair and deepening of the voice, and infertility. Some individuals may also experience psychological and emotional effects related to body image. Treatment focuses on hormone replacement therapy with testosterone, which is typically started around the time of expected puberty to promote normal male development. Testicular prostheses (artificial testicles) can be surgically placed for cosmetic purposes and to improve self-esteem. While fertility is not possible in bilateral (both sides) cases, individuals with unilateral (one side) agenesis may retain fertility through the remaining testicle.
Also known as:
Key symptoms:
Empty scrotum on one or both sidesAbsence of one or both testiclesDelayed puberty if both testicles are missingLack of facial and body hair developmentVoice not deepening during teenage yearsSmall or underdeveloped penis in some casesReduced muscle massInfertilityLow energy or fatigue without hormone treatmentEmotional distress or body image concernsPossible ambiguous genitalia if loss occurred very early in fetal lifeDecreased bone density without testosterone replacement
Clinical phenotype terms (11)— hover any for plain English
Variable
Can be inherited in different ways depending on the underlying gene
Neonatal
Begins at or shortly after birth (first 4 weeks)
FDA & Trial Timeline
1 eventUniversity Hospital, Ghent
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Testicular agenesis.
1 clinical trialare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Testicular agenesis.
Community
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Start the conversation →Latest news about Testicular agenesis
Disease timeline:
New recruiting trial: Prospective Observational Study on SEBBIN Silicone Gel-filled Testicular Implants
A new clinical trial is recruiting patients for Testicular agenesis
Caregiver Resources
NORD Caregiver Resources
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Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.When should testosterone replacement therapy be started, and what form is best for my child?,How will we monitor hormone levels and adjust treatment over time?,Are there any risks or side effects of long-term testosterone therapy I should know about?,Should we consider testicular prostheses, and at what age is this typically done?,Is genetic testing recommended to look for an underlying cause?,What are the options for fertility in the future, and should we consult a reproductive specialist?,Can you recommend a psychologist or counselor who has experience with this type of condition?
Common questions about Testicular agenesis
What is Testicular agenesis?
Testicular agenesis, also known as anorchia or vanishing testes syndrome, is a rare condition in which one or both testicles are completely absent at birth in a person who has male chromosomes (46,XY). The condition is different from undescended testicles, where the testicles exist but have not moved into the scrotum. In testicular agenesis, the testicles either never fully developed or were lost during fetal development, possibly due to a disruption in blood supply (called testicular torsion) while the baby was still in the womb. Because the testicles are responsible for producing testosteron
At what age does Testicular agenesis typically begin?
Typical onset of Testicular agenesis is neonatal. Age of onset can vary across affected individuals.
Are there clinical trials for Testicular agenesis?
Yes — 1 recruiting clinical trial is currently listed for Testicular agenesis on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Testicular agenesis?
2 specialists and care centers treating Testicular agenesis are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.