Overview
Ataxia-telangiectasia variant (also called AT variant or A-T variant) is a rare genetic condition that is closely related to classic ataxia-telangiectasia (A-T) but tends to have a milder or later-onset course. Like classic A-T, this condition is caused by changes in the ATM gene, which plays a key role in repairing damaged DNA and supporting the immune system. However, in the variant form, some ATM protein function is preserved, which is why symptoms are generally less severe. People with A-T variant typically develop progressive problems with balance and coordination (ataxia), though these symptoms may appear later in childhood, adolescence, or even adulthood rather than in early childhood as seen in classic A-T. The small, visible blood vessels on the skin or eyes (telangiectasias) that are a hallmark of classic A-T may be mild or absent in the variant form. Immune system problems can occur but are often less pronounced. An important concern is an increased risk of cancer, particularly blood cancers like lymphoma and leukemia, as well as breast cancer in female carriers. There is currently no cure for A-T variant. Treatment focuses on managing symptoms, monitoring for infections and cancers, and supporting mobility and quality of life through physical therapy and rehabilitation. Immunoglobulin replacement therapy may be used if immune deficiency is significant. Research into targeted therapies and gene-based treatments is ongoing but not yet available as standard care.
Also known as:
Key symptoms:
Progressive difficulty with balance and coordinationUnsteady walking (ataxia)Slurred or slow speechInvoluntary jerky eye movementsSmall visible blood vessels on the eyes or skin (telangiectasias), which may be mild or absentWeakened immune system leading to frequent infectionsIncreased risk of cancer, especially lymphoma and leukemiaMuscle weakness or stiffnessTremor or involuntary movementsDifficulty with fine motor tasks like writingElevated alpha-fetoprotein (AFP) levels in the bloodSensitivity to radiation (such as X-rays)Peripheral neuropathy (numbness or tingling in hands and feet)
Autosomal recessive
Passed on when both parents carry the same gene change; often skips generations
Variable
Can begin at different ages, from infancy through adulthood
FDA & Trial Timeline
8 eventsHyung Keun Park — NA
The Levine Center for Plastic Surgery — NA
AO GENERIUM — PHASE1, PHASE2
European Institute of Oncology — PHASE2
National University of Malaysia — NA
Technische Universität Dresden
Marc Dall'Era, MD — PHASE2
Massachusetts General Hospital
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Ataxia-telangiectasia variant.
4 clinical trialsare 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 Ataxia-telangiectasia variant.
Community
No community posts yet. Be the first to share your experience with Ataxia-telangiectasia variant.
Start the conversation →Latest news about Ataxia-telangiectasia variant
Disease timeline:
New recruiting trial: Long-Term Efficacy and Duration of MFU-V at Multiple Depths and at 1.5 mm
A new clinical trial is recruiting patients for Ataxia-telangiectasia variant
New recruiting trial: Evaluation of a Flexible and Integrative Psychiatric Care Model at the Pfalzklinikum (EVA_Pfalz)
A new clinical trial is recruiting patients for Ataxia-telangiectasia variant
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
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.How much ATM protein function does my child (or I) have, and what does that mean for the expected course of the disease?,What cancer screening schedule should we follow, and what types of cancer are we most at risk for?,Are there any medications, imaging tests, or treatments we should avoid because of radiation sensitivity?,What therapies (physical, occupational, speech) would be most helpful right now?,Should family members be tested for ATM carrier status, and what does being a carrier mean for their health?,Are there any clinical trials or research studies we could participate in?,How often should immune function be checked, and when would immunoglobulin replacement therapy be recommended?
Common questions about Ataxia-telangiectasia variant
What is Ataxia-telangiectasia variant?
Ataxia-telangiectasia variant (also called AT variant or A-T variant) is a rare genetic condition that is closely related to classic ataxia-telangiectasia (A-T) but tends to have a milder or later-onset course. Like classic A-T, this condition is caused by changes in the ATM gene, which plays a key role in repairing damaged DNA and supporting the immune system. However, in the variant form, some ATM protein function is preserved, which is why symptoms are generally less severe. People with A-T variant typically develop progressive problems with balance and coordination (ataxia), though these
How is Ataxia-telangiectasia variant inherited?
Ataxia-telangiectasia variant follows a autosomal recessive inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
Are there clinical trials for Ataxia-telangiectasia variant?
Yes — 4 recruiting clinical trials are currently listed for Ataxia-telangiectasia variant on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Ataxia-telangiectasia variant?
2 specialists and care centers treating Ataxia-telangiectasia variant are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.