Boder–Sedgwick syndrome—better known as Ataxia–Telangiectasia (A-T)—is a rare, inherited condition caused by faults (mutations) in the ATM gene. Children typically develop unsteady movement (ataxia), small widened blood vessels in the eyes/skin (telangiectasia), immune weakness with repeated chest/ear/sinus infections, and a higher lifetime risk of certain cancers. A-T cells are extremely sensitive to X-rays and other ionizing radiation. Management focuses on supportive, preventive, and complication-directed care by a multidisciplinary team; there is no single curative drug at present. BioMed Central+2NCBI+2
A-T is an autosomal-recessive DNA repair disorder in which loss of ATM kinase signaling weakens cellular responses to double-strand DNA breaks. Neurons of the cerebellum degenerate over time (ataxia, slurred speech), small surface blood vessels dilate (telangiectasias), and immune defects (especially IgA/IgG subclass deficiencies and defective class-switch recombination) predispose to repeated respiratory infections. A-T confers marked radiosensitivity and a heightened risk of leukemia/lymphoma and some solid tumors; careful cancer surveillance and non-ionizing imaging strategies are recommended. There is no cure; coordinated supportive care (physiotherapy, airway clearance, vaccination plans, infection control, nutrition, and tailored oncology protocols) can improve quality and length of life. Wiley Online Library+3BioMed Central+3NCBI+3
Boder–Sedgwick syndrome is another name for ataxia–telangiectasia (A-T), a rare, inherited childhood disease. It mainly affects the brain area that controls balance and coordination (the cerebellum), causes small widened blood vessels on the eyes and skin (telangiectasia), weakens the immune system, and makes the body very sensitive to radiation. Children usually begin to show poor balance and clumsy walking in early childhood. Over time, many need a wheelchair. People with A-T also catch infections easily and have a higher risk of certain cancers. The condition happens when both copies of the ATM gene do not work. This gene normally helps repair broken DNA. When ATM is missing or weak, cells cannot repair DNA damage well, which leads to the many features of A-T. NINDS+2NCBI+2
Where the name comes from. The syndrome was described in detail in the 1950s by Boder and Sedgwick, and it is also known as Louis-Bar syndrome. These names reflect the doctors who recognized the pattern of ataxia, telangiectasia, and frequent infections. PubMed+2PMC+2
Other names
Doctors and textbooks may use any of the following for the same condition:
Ataxia–telangiectasia (A-T)
Boder–Sedgwick syndrome (sometimes misspelled as “Border-Sedgwick”)
Louis-Bar syndrome
Cerebello-oculocutaneous telangiectasia
Immunodeficiency with ataxia–telangiectasia
These alternate names appear across neurology and genetics references and patient resources. NINDS+2Social Security Administration+2
Types
Doctors often talk about two broad forms of A-T, based on how much ATM function remains:
Classic A-T. This is the common and more severe form, starting in early childhood with unsteady walking, eye movement problems, telangiectasia, repeated infections, and a higher risk of leukemia and lymphoma. People are very sensitive to medical radiation (like standard radiation therapy). BioMed Central+1
Variant (attenuated) A-T. In this form, there is some residual ATM activity. Symptoms can start later, may progress more slowly, and sometimes the immune problems are milder. Cancers (including breast cancer) can still occur, and radiation sensitivity remains a concern. Genetic testing and measurement of ATM protein or kinase activity can help separate variant from classic A-T. NCBI+1
Clinicians may also describe neurologic-predominant, immunodeficiency-predominant, or malignancy-predominant presentations, but they all fall under A-T caused by ATM variants. ScienceDirect
Causes
A-T does not happen because of something a parent did during pregnancy or anything a child did. It is an autosomal recessive genetic condition. Below are 20 clear, evidence-based “causes/drivers” that either create A-T or make its features worse:
Biallelic ATM variants: A child inherits two non-working copies of the ATM gene (one from each parent). This is the root cause. NCBI
Loss of ATM protein function: ATM normally coordinates repair of DNA double-strand breaks; loss causes genome instability. BioMed Central
Nonsense or frameshift variants: These often abolish ATM protein production and lead to classic A-T. NCBI
Splice-site variants: Can reduce but not eliminate ATM function, sometimes causing variant A-T. NCBI
Missense variants: Single-letter DNA changes can weaken ATM’s enzyme (kinase) activity; severity varies. NCBI
Large deletions/duplications in ATM: Copy-number changes can disrupt the gene. NCBI
Founder variants in certain populations: Some communities have common ATM mutations due to shared ancestry. BioMed Central
Autosomal recessive inheritance patterns (including consanguinity) increase the chance both parents carry the same ATM variant. NCBI
Defective cell-cycle checkpoints: Without ATM, cells don’t pause to fix DNA, leading to errors and cell death or cancer. Wikipedia
Defective V(D)J recombination surveillance: Immune cells need ATM during antibody/T-cell receptor gene rearrangement; failure leads to immunodeficiency. BioMed Central
Oxidative stress sensitivity: ATM also responds to oxidative damage; dysfunction amplifies tissue injury over time. BioMed Central
Neurodegeneration of cerebellum: Ongoing DNA damage and poor repair injure Purkinje and other neurons, causing ataxia. ScienceDirect
Abnormal blood vessel regulation: Leads to visible telangiectasia on eyes/skin. NINDS
Radiation sensitivity: Even standard doses of ionizing radiation cause extra harm; this is due to missing ATM-mediated repair. NCBI
Chromosome instability: Cells show chromosomal breakage and translocations, especially in immune cells. BioMed Central
Cancer predisposition: Faulty DNA damage response increases risk of leukemia, lymphoma, and some solid tumors. BioMed Central
Infection-triggered decline: Recurrent chest infections can worsen lung function and overall health. Cleveland Clinic
Nutritional stress from feeding/swallow problems can aggravate weakness and infection risk. BioMed Central
Hormonal/endocrine issues (e.g., growth problems) can add to fatigue and frailty. Verywell Health
Carriers and family planning: Parents with one non-working ATM copy are usually healthy but may have modestly higher cancer risks; understanding this helps explain recurrence risk. NCBI
Symptoms and signs
Unsteady walking (ataxia). Children start to walk at a normal age but remain wobbly and clumsy. Balance slowly gets worse, and many need a wheelchair in later childhood or adolescence. Wikipedia
Eye telangiectasia. Tiny red blood vessels appear on the white of the eyes, usually by school age. They look like constant “bloodshot” eyes but don’t itch or hurt. Wikipedia
Skin telangiectasia. Small widened vessels can also appear on sun-exposed skin, especially the face and ears. Wikipedia
Frequent infections. Because the immune system is weak, children get repeated ear, sinus, and chest infections. Some develop chronic lung disease. NINDS+1
Eye-movement problems (oculomotor apraxia). The eyes have trouble starting quick movements to look at a new target, making reading hard. Wikipedia
Slurred speech and swallowing trouble. Speech may become slow or slurred, and swallowing can be difficult, raising the risk of choking or aspiration. BioMed Central
Involuntary movements. Some people develop chorea (fidgety jerks), dystonia (twisting postures), tremor, or myoclonic jerks. Wikipedia
Weak or low muscle tone. Posture and endurance are affected; physical fatigue is common. ScienceDirect
Growth problems. Short stature and delayed puberty can occur, sometimes linked to hormone imbalance or chronic illness. Verywell Health
Learning and school challenges. Intelligence can be normal, but motor and eye-movement problems make writing and reading slow; fatigue also reduces school performance. BioMed Central
Chronic lung disease. Recurrent infections, weak cough, and swallowing into the airway can lead to bronchiectasis and long-term breathing problems. BioMed Central
Cancer risk. Leukemia and lymphoma are more common, and some adults (especially female carriers and variant A-T) have higher breast cancer risk. BioMed Central+1
Skin problems. Dry skin, poor wound healing, and photosensitivity may occur. BioMed Central
Endocrine/metabolic issues. Diabetes or insulin resistance can appear in some people with A-T. BioMed Central
Extreme sensitivity to radiation. Medical radiation (like radiotherapy) can cause unusually severe side effects and must be avoided or minimized. NCBI
Diagnostic tests
A) Physical examination
Neurologic exam for coordination. The clinician watches walking, standing, finger-to-nose, and heel-to-shin movements. Wobbly, wide-based walking and poor coordination point toward ataxia. Cleveland Clinic
Eye and skin inspection. The doctor looks for telangiectasia on the whites of the eyes and sun-exposed skin. These are typical clues in school-age children. NINDS
Eye-movement testing. The clinician checks how quickly and smoothly eyes jump (saccades). Slow or delayed starts suggest oculomotor apraxia. Wikipedia
Growth and puberty check. Height, weight, and sexual development are monitored to spot growth delay or hormonal problems early. Verywell Health
Lung and swallowing assessment. Listening to the lungs, checking cough strength, and observing for choking signs help detect aspiration and infection risk. BioMed Central
B) Bedside/manual tests
Timed gait and balance tasks. Simple timed walks, standing with feet together, or one-leg stance can document ataxia severity over clinic visits. ScienceDirect
Functional hand tests. Tasks like rapid finger tapping or spiral drawing record tremor and fine-motor control in a practical way. ScienceDirect
Speech and swallow evaluations. Bedside screens by speech-language therapists identify dysarthria and unsafe swallowing before moving to imaging. BioMed Central
C) Laboratory and pathological tests
Serum alpha-fetoprotein (AFP). AFP is often elevated in A-T after infancy. While not exclusive to A-T, a high AFP supports the diagnosis. BioMed Central
Immunoglobulin levels (IgG, IgA, IgM). Many people with A-T have low IgA or IgG subclasses, explaining frequent infections. BioMed Central
Lymphocyte subsets. Flow cytometry can show low numbers of certain B or T cells, consistent with combined immunodeficiency. BioMed Central
ATM protein quantity and kinase activity. Specialized labs measure how much ATM protein is present and whether it works. Low or absent results are strong evidence. NCBI
Chromosome breakage or translocation studies. Immune cells may show characteristic rearrangements, reflecting DNA repair failure. BioMed Central
Genetic testing of the ATM gene. Sequencing and copy-number analysis identify the exact variants on both copies of ATM, confirming the diagnosis and allowing family testing. NCBI
Carrier testing and prenatal/embryo testing (as desired). Once the family’s ATM variants are known, relatives can be tested, and future pregnancies can be planned with options. NCBI
D) Electrodiagnostic tests
Nerve conduction studies and EMG. These can show peripheral neuropathy in some people, explaining weakness or numbness. ScienceDirect
Evoked potentials (visual or somatosensory). These tests measure how fast signals travel in the nervous system and can reveal slowed pathways in A-T. ScienceDirect
E) Imaging tests
Brain MRI. MRI often shows cerebellar atrophy (shrinkage), especially in the vermis, matching the balance problems. MRI also helps rule out other causes of ataxia. ScienceDirect
Chest CT or MRI (when needed). Imaging can evaluate bronchiectasis or chronic lung disease from repeated infections or aspiration. Radiation exposure should be minimized, so MRI or low-dose protocols are preferred. BioMed Central
Breast imaging in adults (risk-adapted). Because of radiation sensitivity and cancer risk, centers use MRI or carefully tailored strategies rather than standard mammography in some contexts; decisions are individualized. NCBI+1
Non-pharmacological treatments
Physiotherapy (PT): balance, posture, and coordination training to slow mobility loss and reduce falls; home exercise programs maintain function. Edge Hill University
Occupational therapy (OT): energy conservation, adaptive tools (utensils, writing aids), and home/school modifications to maximize independence. Edge Hill University
Speech–language therapy: dysarthria strategies, augmentative communication when needed; swallow therapy to reduce aspiration risk. BioMed Central
Airway clearance techniques: manual chest physiotherapy, oscillatory devices, and breathing exercises to limit mucus plugging and infections. BioMed Central
Pulmonary rehabilitation: structured education/exercise to improve symptoms and reduce exacerbations. BioMed Central
Nutrition counseling: high-calorie, high-protein plans; texture modification for dysphagia; vitamin D/calcium optimization. BioMed Central
Enteral feeding (e.g., gastrostomy) when needed: supports growth, reduces aspiration with thickened/pureed feeds. BioMed Central
Infection prevention training: hand hygiene, masks during outbreaks, home nebulizer hygiene, prompt sputum culture pathways. BioMed Central
Vaccination planning: inactivated vaccines per schedule; avoid live vaccines in some immunodeficient states based on immunology advice. BioMed Central
Sun/UV protection: hats/sunscreen to limit telangiectasia irritation and skin cancer risk. BioMed Central
School accommodations: extra time, physical access, rest breaks, assistive tech, individualized education plan. Edge Hill University
Psychological support: coping skills, anxiety/depression screening for child and caregivers. Edge Hill University
Mobility aids: ankle-foot orthoses, canes/walkers, wheelchairs as needed to maintain participation and safety. Edge Hill University
Scoliosis monitoring & bracing: orthopedic input for posture and comfort. BioMed Central
Sleep/aspiration prevention strategies: upright feeds, safe sleep position, reflux management planning. BioMed Central
Non-ionizing imaging pathways: MRI/ultrasound first to minimize radiation exposure in a radiosensitive disorder. BioMed Central
Cancer awareness & rapid-access review if red flags appear (nodes, fevers, weight loss). Medscape
Genetic counseling for family planning and carrier testing discussions. NCBI
Care coordination (multidisciplinary clinic): neurology, pulmonology, immunology, rehab, nutrition, and oncology working together improves outcomes. Cureus
Community nursing & home-based AHP support: structured domiciliary programs reduce complications and hospitalizations. Edge Hill University
Drug treatments
Dosages must be individualized by the treating team; below are typical uses with plain-language purposes. (Full 150-word monographs with class/dose/timing/mechanism/side-effects can be expanded on request.)
IVIG / SCIG (immune globulin): for significant antibody deficiency or poor vaccine responses—reduces severe infections; adverse effects include headache, infusion reactions, rare thrombosis. BioMed Central
Antibiotics (culture-guided): oral/IV courses for bacterial sinusitis/otitis/pneumonia; stewardship is essential. BioMed Central
Azithromycin (long-term, selected cases): anti-inflammatory/anti-infective prophylaxis in bronchiectasis under specialist guidance. BioMed Central
Inhaled bronchodilators (e.g., salbutamol): ease wheeze and airflow obstruction during exacerbations. BioMed Central
Inhaled corticosteroids: for co-existing asthma-like inflammation; monitor growth/oral thrush. BioMed Central
Hypertonic saline / nebulized mucolytics: thin mucus to aid clearance. BioMed Central
Proton-pump inhibitors (e.g., omeprazole): treat reflux to lower aspiration risk; long-term use requires monitoring (bone, infections). BioMed Central
Antitussives/expectorants (selected): symptomatic cough support—short courses only. BioMed Central
Antihistamines / intranasal steroids: allergic rhinitis control to reduce sinus complications. BioMed Central
Antiviral therapies as indicated: e.g., oseltamivir/antivirals per guidelines during influenza or other viral risks. BioMed Central
Hematology/oncology regimens tailored for radiosensitivity: chemotherapy dose adjustments; avoid radiotherapy where feasible. Medscape
Growth hormone therapy (selected, with endocrinology): treat GH deficiency; requires cancer-risk counselling. BioMed Central
Spasticity/tremor medications (e.g., baclofen, clonazepam): symptomatic relief for movement disorders; sedation is common. BioMed Central
Antiepileptics when seizures occur; choice individualized. BioMed Central
Nebulized antibiotics (e.g., tobramycin) for chronic airway colonization in bronchiectasis—specialist protocols. BioMed Central
Vaccines (inactivated): influenza, pneumococcal, etc., per immunology plan; avoid live vaccines in some patients. BioMed Central
Antimycotics for fungal airway/sinus disease when documented. BioMed Central
Analgesics for musculoskeletal pain from falls/orthopedic issues; avoid excessive NSAIDs if gastritis present. BioMed Central
Antiemetics during chemotherapy or severe cough-triggered nausea. Medscape
Nicotinamide riboside chloride (investigational): received FDA Orphan & Rare Pediatric Disease designations for A-T; clinical efficacy still under study—do not self-start without a trial protocol. The Wall Street Journal
Dietary / molecular supplements
Evidence for supplements in A-T is limited/experimental; discuss with the care team before use.
Nicotinamide riboside (NR): NAD+ precursor under orphan designation for A-T; mechanistic rationale targets mitochondrial/DNA repair pathways; safety/benefit in A-T remains investigational. The Wall Street Journal
Vitamin D: supports bone and immune health; dose per 25-OH level. BioMed Central
Omega-3 fatty acids: anti-inflammatory support for airway/lung health; watch interactions/bleeding risk at high doses. BioMed Central
Vitamin E: antioxidant support; excess may increase bleeding; evidence in A-T is not definitive. BioMed Central
Vitamin C: general antioxidant/immune support; GI tolerance limits dose. BioMed Central
N-acetylcysteine (NAC): mucolytic/antioxidant; may aid sputum clearance in bronchiectasis care pathways. BioMed Central
Zinc: immune function cofactor; avoid excess (copper deficiency). BioMed Central
Selenium: antioxidant enzyme cofactor; narrow therapeutic window. BioMed Central
Probiotics: gut/immune support in selected patients; strain-specific evidence; avoid in severe immunodeficiency. BioMed Central
Curcumin (experimental): anti-inflammatory/antioxidant mechanisms; variable bioavailability and limited clinical data in A-T. BioMed Central
Immunity-booster / regenerative / stem-cell-related” drug concepts
IVIG/SCIG (immune replacement): enhances pathogen-specific antibodies; cornerstone for humoral immunodeficiency in A-T. BioMed Central
G-CSF (selected hematology indications): boosts neutrophil counts in treatment-related neutropenia; specialist use only. Medscape
Hematopoietic stem-cell transplant (HSCT)–adjacent regimens: conditioning drugs must be radically adapted (A-T radiosensitivity); HSCT is not routine and remains controversial. BioMed Central
NAD+ boosters (e.g., NR) in trials: aim to improve cellular stress responses; efficacy unknown. The Wall Street Journal
ATM-pathway targeted agents (experimental): small-molecule modulators/kinase activators explored preclinically; not standard of care. ScienceDirect
Oncologic biologics tailored to A-T: when cancer occurs, regimens avoid radiation and use carefully dosed chemo/targeted agents to limit DNA damage. Medscape
Procedures/surgeries
Gastrostomy tube placement: supports safe nutrition/hydration when oral feeding is unsafe or insufficient; reduces aspiration. BioMed Central
Fundoplication (selected): anti-reflux surgery when severe reflux causes aspiration despite optimized medical care. BioMed Central
Tympanostomy tubes / sinus surgery: for chronic otitis media or refractory sinus disease to cut infection frequency. BioMed Central
Spinal fusion (severe scoliosis): improves sitting balance/pain; careful peri-op respiratory planning needed. BioMed Central
Oncology procedures (biopsy, port placement, tumor surgery): individualized, with strict avoidance of radiotherapy where possible due to radiosensitivity. Medscape
Prevention tips
Keep vaccinations up to date (inactivated types per immunology advice). 2) Hand hygiene and cough etiquette at home/school. 3) Avoid smoke (tobacco, biomass); use clean cooking fuel/ventilation. 4) Prompt treatment plans for cough/fever with a named clinic contact. 5) Daily airway clearance routine when advised. 6) Nutrition first: adequate calories/protein; vitamin D sufficiency. 7) Sun protection for skin/eye telangiectasia care. 8) Avoid unnecessary X-rays/CT scans; prefer MRI/ultrasound. 9) Fall-proof the home/classroom; use mobility aids. 10) Regular multidisciplinary reviews (immunology, pulmonology, rehab, neurology, oncology). BioMed Central+1
When to see a doctor urgently
Breathing trouble, fast breathing, chest pain, or blue lips.
High fever, persistent cough with green/bloody sputum, dehydration, or inability to keep fluids down.
New large, painless lymph nodes; unexplained weight loss; night sweats; easy bruising/bleeding (possible cancer red flags).
Frequent choking, new swallowing problems, or repeated vomiting.
Unusual headaches, seizures, or sudden neurologic changes.
These red flags in A-T warrant same-day medical review because infection and cancer risks are higher than average. BioMed Central+1
What to eat & what to avoid
Prioritize: energy-dense foods (oils, nut butters if safe), lean proteins, dairy/alternatives, fruits/vegetables in easy-to-chew textures, vitamin D-rich foods, adequate fluids.
Modify textures: minced/mashed or thickened liquids if advised to reduce choking/aspiration.
Consider supplements only under guidance (vitamin D, zinc, omega-3, etc.).
Avoid or limit: hard-to-chew dry foods (aspiration risk), highly processed high-salt snacks (worsen reflux), alcohol/caffeine for older teens (dehydrating), and raw/unpasteurized products when immune function is low.
A dietitian familiar with neuromuscular dysphagia can create a safe, enjoyable meal plan. BioMed Central
FAQs
1) Is Boder–Sedgwick syndrome the same as A-T?
Yes. Boder and Sedgwick’s 1958 paper established the modern description of A-T. PubMed
2) Is “Louis-Bar syndrome” correct?
It appears in older literature but is historically problematic; A-T or Boder–Sedgwick are preferred. ScienceDirect
3) How common is A-T?
Roughly 1 in 40,000–100,000 births worldwide. BioMed Central
4) Do carriers (one faulty ATM copy) have risks?
Carriers may have a higher cancer risk and some radiosensitivity; they should discuss screening with clinicians. NCBI
5) What age do symptoms start?
Usually in the first decade (delayed motor skills, falls, slurred speech). Social Security Administration
6) Is there a cure?
No cure yet; care focuses on prevention and managing complications with a multidisciplinary team. Cureus
7) Can we do X-rays or CT scans?
Only if absolutely necessary and using the lowest possible dose; prefer MRI/ultrasound first. BioMed Central+1
8) What cancers are most common?
Childhood leukemias/lymphomas predominate; adult breast cancer risk is also elevated (including in carriers). Medscape+1
9) Is there a standard cancer screening program?
Work is ongoing; no universally accepted A-T-specific guideline exists yet, so decisions are individualized. Wiley Online Library
10) Which vaccines are safe?
Inactivated vaccines are usually recommended; live vaccines require immunology input case-by-case. BioMed Central
11) Will school be affected?
Intelligence is often unaffected early, but motor/speech/health issues need school accommodations and therapy support. Social Security Administration+1
12) Can exercise help?
Yes—safe, supervised PT/OT helps maintain function and reduce falls. Edge Hill University
13) Should families get genetic testing?
Genetic counseling and testing help identify carriers and plan pregnancies. NCBI
14) Are supplements useful?
Some (vitamin D, omega-3s) can support general health; evidence in A-T is limited—always discuss with clinicians. BioMed Central
15) What research looks promising?
Nicotinamide riboside (NR) has FDA orphan status; more trials are needed. Gene-targeted approaches are under study. The Wall Street Journal+1
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The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members
Last Updated: September 24, 2025.
