1p36 Deletion Syndrome Hub
One place for in-depth information, research, and practical tools
for families and caregivers living with 1p36 deletion syndrome.
1p36 is one of the most common chromosomal microdeletion syndromes. Here you will find peer-reviewed information, links to active research, and connections to the global patient community.
What is 1p36?
Overview of the syndrome
Clinical Features
Signs, symptoms, and variability
Diagnosis & Genetics
How it is identified and inherited
Medical Management
Specialist care and monitoring
Therapy & Interventions
PT, OT, speech, and communication
Research
Current studies and gene discoveries
Daily Life
Education, inclusion, and routines
Family & Caregivers
Support, wellbeing, and planning
Resources & Links
Organizations, registries, and guides
What is 1p36 Deletion Syndrome?
Overview, prevalence, and cause of the most common terminal chromosomal deletion
What is 1p36 Deletion Syndrome?
A chromosomal disorder caused by the loss (deletion) of genetic material at the very tip of the short arm (p) of chromosome 1, at position 36. It is one of the most common subtelomeric chromosomal microdeletion syndromes. The amount of missing DNA varies between individuals, which explains the wide range of features seen across affected children and adults.
How Common Is It?
Estimated to affect approximately 1 in 5,000 live births worldwide, making it one of the more frequent chromosomal microdeletion syndromes. An estimated 40,000 individuals with 1p36 deletion syndrome live in the United States alone. It affects all ethnic groups equally and is slightly more common in females than males.
What Causes It?
In about 60% of cases, the deletion arises as a de novo (new) mutation — not inherited from either parent. In other cases it results from a chromosomal rearrangement inherited from a parent. The deleted region contains many genes; the size of the deletion (which varies from less than 1 Mb to over 10 Mb) strongly influences how severely a person is affected.
Recurrence Risk for Families
When a deletion is de novo, the recurrence risk for future pregnancies is approximately 1%. When a parent carries a chromosomal rearrangement that led to the deletion, the risk may be significantly higher and depends on the type of rearrangement. Genetic counselling is strongly recommended for all families after diagnosis.
Frequently Asked Questions
Clinical Features
Signs and symptoms — and why they vary so much between individuals
High Variability
The features of 1p36 deletion syndrome vary enormously from person to person. The size and location of the deletion, along with other genetic and environmental factors, determine which features are present and how severely. No single feature is present in every individual with the syndrome.
Core Features by Body System
| System | Common Features | Approximate Frequency |
|---|---|---|
| Neurological | Intellectual disability (typically moderate to severe), epilepsy, hypotonia (low muscle tone) | Epilepsy: ~44–70%; Hypotonia: ~90%+ |
| Cardiac | Congenital heart defects (dilated cardiomyopathy, septal defects, patent ductus arteriosus) | ~43–71% |
| Developmental | Delayed milestones (motor, speech, cognitive), absent or limited speech | Nearly universal |
| Craniofacial | Large anterior fontanelle, flat nasal bridge, deep-set eyes, pointed chin, short philtrum | Common |
| Behavioural | Aggression, self-injurious behaviour, features overlapping with autism spectrum disorder | ~40–65% |
| Hearing & Vision | Sensorineural hearing loss, refractive errors, strabismus | Hearing loss: ~50–70% |
| Musculoskeletal | Scoliosis, joint laxity, feeding difficulties in infancy | Variable |
| Endocrine | Hypothyroidism, obesity in older individuals | Variable |
The Most Common Medical Challenges
Epilepsy
Seizures are one of the most significant medical features. They often begin in infancy or early childhood and can be difficult to control. Multiple seizure types may be present in the same individual. Drug-resistant epilepsy is common. Close collaboration with a paediatric neurologist (and eventually an adult neurologist) is essential.
Heart Defects
Congenital heart defects are present in a large proportion of individuals. Dilated cardiomyopathy is specifically associated with 1p36 deletion and may develop over time even if the heart appeared normal at birth. Regular cardiac monitoring is essential throughout life, not just in infancy.
Communication Challenges
Most individuals with 1p36 deletion have absent or severely limited spoken language. However, many can communicate effectively using augmentative and alternative communication (AAC) methods such as picture exchange systems (PECS), speech-generating devices, or sign language. Do not underestimate communication potential.
Diagnosis & Genetics
How 1p36 deletion syndrome is identified and what the genetic tests mean
Chromosomal Microarray (CMA)
The gold standard diagnostic test. Also called array comparative genomic hybridisation (aCGH) or SNP array. It can detect deletions as small as a few hundred kilobases. CMA is now recommended as the first-tier genetic test for children with unexplained intellectual disability, autism spectrum disorder, or multiple congenital anomalies.
FISH (Fluorescence In Situ Hybridisation)
An older test that was historically used to confirm 1p36 deletions but cannot detect the full size of the deletion. FISH is now largely replaced by microarray as a first-line test, but may be used for targeted confirmation or to test parents after a child has been diagnosed.
Whole Exome / Genome Sequencing
Increasingly used in complex cases where microarray does not explain all features. Can identify additional genetic variants that may modify the clinical picture. Some research programmes use whole genome sequencing to better understand gene-phenotype relationships in 1p36 deletion syndrome.
When Should Testing Be Considered?
Testing for 1p36 deletion syndrome should be considered in any child with: unexplained intellectual disability or developmental delay, absent or minimal speech, hypotonia (low muscle tone), seizures of unknown cause, congenital heart defect combined with developmental delay, or characteristic facial features described above. Prenatal diagnosis is possible via chorionic villus sampling (CVS) or amniocentesis if a parent is known to carry a chromosomal rearrangement.
Parental Testing and Inheritance
Why Test Parents?
After a child is diagnosed, both parents should be offered chromosomal testing. In approximately 40% of cases, a parent carries a chromosomal rearrangement (translocation or inversion) that did not cause them any problems but led to the deletion in the child. Knowing this is critical for determining the recurrence risk for future pregnancies.
Mosaic 1p36 Deletion
A small proportion of individuals have a mosaic form, where only some cells in the body carry the deletion. Mosaicism often (but not always) results in milder features. Standard microarray may miss low-level mosaicism; SNP arrays or next-generation sequencing may be needed to detect it.
The Role of Genetic Counselling
A clinical geneticist or genetic counsellor can explain the results, clarify the recurrence risk, discuss reproductive options (including preimplantation genetic testing), and help families understand what the deletion means for the affected individual's long-term health and development.
Medical Management
Specialist care, monitoring schedules, and managing key medical complications
Multidisciplinary Team Approach
Because 1p36 deletion syndrome affects multiple body systems, management requires a coordinated team of specialists. The team typically includes a clinical geneticist, paediatric neurologist (for epilepsy), cardiologist, developmental paediatrician, audiologist, ophthalmologist, endocrinologist, and therapists (speech, occupational, physical). A paediatric subspeciality centre with experience in chromosomal syndromes is ideal.
Cardiac Management
At Diagnosis
All individuals with confirmed 1p36 deletion should have an echocardiogram at the time of diagnosis, even if no heart defect is suspected clinically. This is because cardiac defects — including dilated cardiomyopathy — can be present without obvious symptoms in infancy.
Dilated Cardiomyopathy
Dilated cardiomyopathy (DCM) is a specific concern in 1p36 deletion syndrome and can develop after a normal cardiac assessment in infancy. Regular echocardiographic monitoring throughout childhood and adolescence is recommended. If DCM is diagnosed, cardiology management follows standard paediatric heart failure protocols.
Structural Defects
Common structural defects include ventricular and atrial septal defects and patent ductus arteriosus. These may require surgical or catheter-based correction. Outcomes from cardiac surgery in children with 1p36 deletion are generally good when the procedure is performed by experienced teams.
Neurology & Epilepsy Management
Drug-Resistant Epilepsy
Seizures in 1p36 deletion syndrome are often difficult to control and may require multiple anti-seizure medications (polypharmacy). Some individuals may benefit from the ketogenic diet, vagus nerve stimulation (VNS), or other non-pharmacological approaches when medications fail. Close neurological follow-up is essential.
Seizure Types
Multiple seizure types are common, including infantile spasms, focal seizures, tonic-clonic seizures, and absence seizures. An EEG (electroencephalogram) is important for characterising seizure type and guiding medication choice. Brain MRI may reveal structural abnormalities such as cortical dysplasia or white matter changes.
Hypotonia and Motor Development
Almost all individuals with 1p36 deletion have central hypotonia (low muscle tone). This contributes to delayed motor milestones, feeding difficulties in infancy, and impaired coordination. Early physiotherapy is key to supporting motor development. Some individuals never achieve independent walking; others walk with support or independently with some delay.
Sleep Disturbances
Sleep problems including difficulty falling asleep, frequent waking, and disordered sleep patterns are common in 1p36 deletion syndrome and in chromosomal syndromes generally. These can significantly affect family quality of life. Melatonin and sleep hygiene strategies are often helpful; refer to a paediatric sleep specialist if needed.
Other Medical Systems
Hearing
Sensorineural hearing loss is present in 50–70% of individuals. Audiological assessment should be performed at diagnosis and regularly thereafter. Hearing aids can significantly improve language learning outcomes. Consider referral to a paediatric audiologist and a specialist in communication for children with hearing loss and cognitive disability.
Vision
Refractive errors (nearsightedness, farsightedness) and strabismus are common. Ophthalmological evaluation is recommended at diagnosis. Glasses and/or patching therapy for amblyopia should be initiated early to optimise visual development. Cortical visual impairment is also seen in some individuals.
Hypothyroidism & Endocrine
Hypothyroidism occurs in a subset of individuals and should be screened for at diagnosis and periodically thereafter. Obesity can develop in adolescence and adulthood and requires dietary and activity-based management. Regular monitoring of weight, thyroid function, and (in later years) metabolic health is advisable.
Feeding Difficulties
Infants with 1p36 deletion often have significant feeding difficulties due to hypotonia and poor oral motor coordination. Some infants require nasogastric or gastrostomy (G-tube) feeding for a period. Early involvement of a feeding therapist and dietitian is important. Most feeding difficulties improve as the child grows and tone increases.
Scoliosis & Orthopaedic
Scoliosis (curvature of the spine) and joint laxity are seen in some individuals. Regular spinal assessment is recommended, especially during the growth years. Physiotherapy can help with posture and muscle strengthening. Bracing or surgery may be needed in severe cases.
Behavioural and Psychiatric
Aggression, self-injurious behaviour, anxiety, and features overlapping with autism spectrum disorder are common. A behavioural specialist, psychologist, or psychiatrist with experience in intellectual disability can help develop management strategies. Some individuals benefit from low-dose psychotropic medications alongside behavioural therapy.
Recommended Monitoring Schedule
| Assessment | At Diagnosis | Ongoing Frequency |
|---|---|---|
| Echocardiogram (heart ultrasound) | Yes | Every 1–2 years or as directed by cardiologist |
| EEG | If seizures suspected | As clinically indicated |
| Brain MRI | Consider | As clinically indicated |
| Audiological assessment | Yes | Annually or every 2 years |
| Ophthalmological assessment | Yes | Annually in early childhood |
| Thyroid function tests | Yes | Every 1–2 years |
| Spinal assessment | Consider | During growth years; annually if scoliosis present |
| Developmental review (OT, PT, Speech) | Yes | Every 6–12 months |
| Weight and growth monitoring | Yes | Every visit |
The Importance of Transition to Adult Care
The transition from paediatric to adult specialist care is a vulnerable period for individuals with 1p36 deletion syndrome. Planning should begin well in advance (around age 14–16). Cardiac monitoring in particular must continue throughout adulthood given the risk of dilated cardiomyopathy developing at any age.
Therapy & Interventions
Physical, occupational, speech therapy, AAC, and behavioural support
Early Intervention Makes a Difference
Research consistently shows that early and intensive intervention significantly improves outcomes for children with chromosomal syndromes including 1p36 deletion. The earlier therapy begins — ideally within the first months of life — the better. Do not wait for a formal diagnosis if there are developmental concerns; early intervention services do not require a specific genetic diagnosis to begin.
Physical Therapy (PT)
Addresses low muscle tone, delayed motor milestones, balance, and coordination. Goals may include improving head control, rolling, sitting, standing, and walking. Hydrotherapy (aquatic physiotherapy) is often enjoyed and beneficial. Ongoing PT into adulthood supports mobility, prevents contractures, and manages scoliosis.
Occupational Therapy (OT)
Focuses on fine motor skills, self-care, sensory processing, and daily living activities. OT can help children and adults learn to feed, dress, and groom themselves to their maximum potential. Sensory integration therapy may be helpful for children with heightened sensory sensitivities.
Speech and Language Therapy (SLT)
Most children with 1p36 deletion will not develop typical spoken language. SLT focuses on pre-linguistic communication skills and introduction of AAC (augmentative and alternative communication). Starting AAC early — even before the child can use it independently — accelerates communication development and reduces frustration.
Augmentative & Alternative Communication (AAC)
AAC includes picture exchange (PECS), communication books, speech-generating devices (SGDs), and eye gaze technology. Modern high-tech AAC devices are highly effective and can give non-speaking individuals a powerful voice. Many individuals with 1p36 deletion learn to use AAC successfully with consistent support from trained therapists, teachers, and family.
Behavioural Support
Applied Behaviour Analysis (ABA) and Positive Behaviour Support (PBS) can help manage challenging behaviours such as aggression and self-injury by identifying triggers and teaching alternative coping strategies. Any approach to challenging behaviour should start by ruling out pain and unmet communication needs as the primary cause.
Feeding Therapy
For infants and young children with oral motor difficulties, a feeding therapist (often a speech-language pathologist or occupational therapist with specialised feeding training) can help develop safe swallowing techniques, appropriate food textures, and mealtime strategies to maximise nutrition and enjoyment of eating.
Research & Science
Current knowledge, key genes, and active research directions
Key Genes in the 1p36 Region
Researchers have identified several genes within the 1p36 region that are particularly important. KCNAB2 (potassium channel subunit) is linked to epilepsy. SKI is associated with craniofacial and cardiac features. GABRD (GABA receptor subunit) contributes to seizure susceptibility. Ongoing genotype-phenotype research aims to match specific gene losses to specific clinical features.
Patient Registries
International patient registries are critical for rare disease research. The 1p36 Deletion Support & Awareness Group supports a patient registry that collects natural history data. The more families who participate, the faster researchers can understand the full spectrum of the condition and identify potential therapeutic targets.
Animal Models
Mouse models with deletions of specific 1p36 orthologue regions are helping researchers understand how individual gene losses contribute to brain development, epilepsy, and cardiac function. These models are a stepping stone toward understanding potential therapeutic approaches for some of the features of the syndrome.
Genotype–Phenotype Research
One of the most active areas of research is mapping which genes cause which features. Large collaborative studies using data from many patients are refining our understanding. This research has practical implications: it helps clinicians predict which medical complications to watch for based on the size and location of a specific individual's deletion.
Whole Genome Sequencing Studies
Large-scale studies are using whole genome sequencing to identify additional genetic variants in individuals with 1p36 deletion that may modify the clinical picture. This "second hit" hypothesis may help explain why two children with similarly sized deletions can have very different outcomes.
Future Therapeutic Directions
While there is currently no disease-modifying therapy for 1p36 deletion syndrome, research into gene therapy, targeted molecular approaches, and precision medicine for related conditions (such as Dravet syndrome, which shares some genetic pathways) may eventually open doors for specific aspects of 1p36 management, particularly epilepsy.
Daily Life & Education
School, routines, inclusion, and quality of life
Educational Settings
Children with 1p36 deletion syndrome typically require specialised educational support with an individualised education programme (IEP or equivalent). Some children attend inclusive mainstream settings with one-to-one support; others thrive in specialised schools. The most effective setting depends on the individual child's abilities, communication needs, and medical requirements.
Predictable Routines
Children and adults with 1p36 deletion often respond very well to predictable daily routines and structured environments. Visual schedules, consistent transitions, and advance warning of changes can significantly reduce anxiety and challenging behaviour. Work with the school team to create consistent routines between home and school.
Play and Leisure
Many individuals with 1p36 deletion enjoy sensory play, music, water, and outdoor activities. Adapted sports and leisure programmes (such as Special Olympics) offer inclusion, physical activity, socialisation, and confidence-building. Interests and preferences are highly individual — finding what a person enjoys is as important as formal therapy.
Home Adaptations
Depending on mobility needs, home adaptations may include stair gates, adapted bathroom equipment, safe sleeping arrangements, and seizure monitoring devices. An occupational therapist can conduct a home assessment and recommend modifications. For children with significant seizure disorders, seizure alert systems and safe sleeping arrangements are especially important.
Transition to Adulthood
Planning for adulthood should begin in early adolescence. Key areas include supported living arrangements, day programmes, supported employment, and ongoing medical care. Work with social services, disability support organisations, and the individual's multidisciplinary team. Adults with 1p36 deletion can live fulfilling lives with appropriate support.
Capturing Progress
Developmental progress in 1p36 deletion syndrome can be slow and hard to measure using standard tools. Video diaries, communication logs, and parent-reported outcome measures are valuable for tracking meaningful gains. Celebrating small milestones matters — every new skill achieved is a genuine accomplishment.
Family & Caregivers
Supporting the whole family — not just the child with the diagnosis
Caregiver Wellbeing Matters
Parents and caregivers of children with 1p36 deletion syndrome experience high rates of stress, anxiety, and caregiver burnout. This is normal and understandable. Seeking support for yourself is not selfish — it makes you a better caregiver. Please prioritise your own mental and physical health.
Connecting with Other Families
One of the most powerful sources of support is connecting with other families living with 1p36 deletion syndrome. The 1p36 Deletion Support & Awareness Group (see Resources) runs active online communities, annual conferences, and family matching programmes. The shared experience of other families is invaluable and cannot be replaced by medical advice alone.
Mental Health Support
Many parents experience grief at diagnosis, ongoing worry, and emotional exhaustion. Psychotherapy, support groups for parents of children with disabilities, and respite care can all help. Do not wait until you are overwhelmed to seek support. Ask your GP, paediatrician, or social worker for a referral.
Siblings
Brothers and sisters of children with 1p36 deletion may feel overlooked, anxious, or confused about their sibling's diagnosis. Sibling support programmes exist in many countries. Age-appropriate, honest communication about the diagnosis helps siblings understand and often strengthens family bonds.
Legal Rights and Entitlements
Children and adults with 1p36 deletion syndrome are entitled to educational support, disability benefits, and care funding in most countries. Families should work with a social worker, disability support organisation, or patient advocacy group to understand what they are entitled to and how to access it. Do not assume support will be offered automatically.
Financial Planning
Caring for a child or adult with 1p36 deletion has significant financial implications. Special needs trusts, government benefits, and charitable grants can help. Consider consulting a financial advisor with experience in disability planning. Connect with your national or local disability charity for guidance on available funding sources.
Respite Care
Regular breaks from caregiving are essential for sustainable long-term caring. Respite care — short-term care provided by trained workers so that family caregivers can rest — is available in many countries through disability support services. Ask your social worker or disability support organisation what is available locally.
Resources & Links
International organizations, registries, and essential reading for families and clinicians
Key Organizations
1p36 Deletion Support & Awareness Group
The primary global patient organisation for families and individuals living with 1p36 deletion syndrome. Offers family matching, an active online community, educational conferences, medical professional consultation, and a patient registry. The single most important resource for newly diagnosed families.
www.1p36dsa.org
NORD — National Organization for Rare Disorders
Provides a comprehensive, clinician-reviewed disease information report on 1p36 deletion syndrome, updated regularly. NORD also advocates for rare disease research funding, patient support programmes, and drug development. An authoritative reference for families seeking reliable medical information.
rarediseases.org
Unique — Rare Chromosome Disorder Support Group
UK-based charity supporting individuals with rare chromosomal disorders including 1p36 deletion. Produces a detailed patient-facing information guide on 1p36 deletion syndrome (available in English and other languages). Excellent resource for families who want a thorough, family-friendly explanation of the condition.
rarechromo.org
Additional Global Resources
Orphanet
European rare disease database with detailed information on 1p36 deletion syndrome including prevalence data, diagnostic criteria, and links to expert centres across Europe. Available in multiple languages.
orpha.net
OMIM — Online Mendelian Inheritance in Man
Comprehensive scientific database of genetic disorders. OMIM entry #607872 covers 1p36 microdeletion syndrome with full genetic and clinical detail. Intended primarily for clinicians and researchers.
omim.org
GeneReviews — NCBI Bookshelf
Peer-reviewed, regularly updated summaries of genetic conditions for clinicians. The 1p36 Deletion Syndrome GeneReview is an authoritative clinical reference covering diagnosis, management, and surveillance recommendations.
ncbi.nlm.nih.gov/books/NBK1191
Essential Links
Want a portal for another condition?
CarePedia builds research-based medical information portals. If you know someone who could benefit, let us know.
Request a portal