Ataxia-telangiectasia syndrome: genes and variants
Ataxia-telangiectasia syndrome is linked to 2 analyzed proteins (ATM and BRAF). 4 DNA variants are known to cause it; 1,026 more are uncertain, and 0 of those already look disease-causing on computable evidence.
Last updated 2026-09-30. Research information, not medical advice.
Genes linked to Ataxia-telangiectasia syndrome
ATM: Serine-protein kinase ATM
It is activated by DNA double-strand breaks and coordinates checkpoint arrest, repair, and apoptosis through phosphorylation of numerous targets. Biallelic loss causes ataxia-telangiectasia, while heterozygous pathogenic variants increase susceptibility to several cancers.
3 disease-causing and 1,026 uncertain variants in ATM are linked to Ataxia-telangiectasia syndrome.
BRAF: Serine/threonine-protein kinase B-raf
It relays activated RAS signals through MEK and ERK to control proliferation, differentiation, and survival. Activating variants, especially V600E, drive melanoma and several other cancers and create sensitivity to pathway-directed therapies.
1 disease-causing and 0 uncertain variants in BRAF are linked to Ataxia-telangiectasia syndrome.
Known disease-causing variants in Ataxia-telangiectasia syndrome
| Variant | Position | Protein part | Clinical label |
|---|---|---|---|
| BRAF V471F | 471 | Protein kinase | Disease-causing (★★) |
| ATM G2765A | 2765 | PI3K/PI4K catalytic | Disease-causing (★★) |
| ATM I2702K | 2702 | PI3K/PI4K catalytic | Disease-causing (★) |
| ATM R2909T | 2909 | PI3K/PI4K catalytic | Disease-causing (★) |
Same protein, different disease
- RASopathy is also caused by BRAF variants; they fall mostly in different places as the Ataxia-telangiectasia syndrome variants (36 disease-causing).
- Cardio-facio-cutaneous syndrome is also caused by BRAF variants; they fall mostly in different places as the Ataxia-telangiectasia syndrome variants (26 disease-causing).
- Cardiofaciocutaneous syndrome is also caused by BRAF variants; they fall mostly in different places as the Ataxia-telangiectasia syndrome variants (17 disease-causing).
- Noonan syndrome is also caused by BRAF variants; they fall mostly in different places as the Ataxia-telangiectasia syndrome variants (11 disease-causing).
- Noonan syndrome and Noonan-related syndrome is also caused by BRAF variants; they fall mostly in different places as the Ataxia-telangiectasia syndrome variants (10 disease-causing).
Diseases related to Ataxia-telangiectasia syndrome
- Colorectal cancer, also linked to ATM and BRAF
- Hypertrophic cardiomyopathy, also linked to BRAF
- RASopathy, also linked to BRAF
- Noonan syndrome, also linked to BRAF
- Noonan syndrome and Noonan-related syndrome, also linked to BRAF
- Cardiofaciocutaneous syndrome, also linked to BRAF
- Ovarian cancer, also linked to ATM
- Cardio-facio-cutaneous syndrome, also linked to BRAF
- Familial cancer of breast, also linked to ATM
- LEOPARD syndrome 1, also linked to BRAF
- Gastric cancer, also linked to ATM
- Non-small cell lung carcinoma, also linked to BRAF
Frequently asked questions
Which genes are linked to Ataxia-telangiectasia syndrome?
In CATVariant, Ataxia-telangiectasia syndrome is linked to 2 analyzed proteins: ATM (Serine-protein kinase ATM) and BRAF (Serine/threonine-protein kinase B-raf).
How many genetic variants are linked to Ataxia-telangiectasia syndrome?
1,031 variants: 4 are classified as disease-causing (pathogenic or likely pathogenic) in ClinVar and 1,026 are of uncertain significance or have conflicting reports.
Which uncertain variants in Ataxia-telangiectasia syndrome look disease-causing?
None of the uncertain variants currently reaches the likely-pathogenic range on computable evidence alone.
About this data
Variant–disease links come from ClinVar, Open Targets and UniProt, pooled from the latest public CATVariant analysis of each human protein. Evidence scores use the ACMG/AMP Bayesian points scale with computable criteria only (position among known disease variants, rarity in gnomAD, calibrated predictors, deep mutational scanning); there is no family or patient data, so they prioritise variants for expert review and never classify them.
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