On this page
Retinoblastoma (hereditary)
This inherited form of retinoblastoma typically appears in both eyes during early childhood, affecting approximately 1 in 15,000 to 20,000 births in the UK. Children who inherit a pathogenic RB1 variant face substantially increased risks of developing retinal tumours, usually before age five, and require specialist monitoring and treatment to preserve vision and prevent life-threatening complications.
Available at Jeen Health
Clinical tests that include this
Overview
Retinoblastoma is a cancer that forms in the light-sensitive tissue at the back of the eye, known as the retina. The hereditary form develops when a child inherits a pathogenic variant in the RB1 gene from either parent, or occasionally when a new variant arises spontaneously during early development. This inherited change means every cell in the child's body carries the altered gene, creating vulnerability to tumour formation in both eyes and, later in life, a heightened risk of developing other cancers.
Children with hereditary retinoblastoma typically develop multiple tumours in both eyes during infancy or early childhood, whereas non-hereditary retinoblastoma usually affects only one eye and occurs slightly later. Early recognition is crucial because treatment outcomes depend significantly on how advanced the tumours are when first detected. With modern NHS ophthalmology and oncology services, many children achieve excellent visual outcomes, though the condition requires lifelong surveillance given the broader cancer risks associated with RB1 variants.
The condition represents one of the most successfully treated childhood cancers when caught early, yet families face complex decisions around treatment approaches, genetic testing of siblings and future children, and long-term monitoring strategies. Access to specialist retinoblastoma centres and clinical genetics services forms an essential part of managing both the immediate cancer risk and the longer-term implications for affected individuals and their relatives.
Symptoms & clinical features
The most characteristic early sign of retinoblastoma is an unusual white reflection in the pupil, often first noticed in flash photographs where the affected eye shows a white glow rather than the typical red-eye effect. Parents may observe this 'cat's eye reflex' or leukocoria when light hits the child's eye at certain angles. Another common presentation involves a squint or strabismus, where the eyes appear misaligned, though this occurs in many children without retinoblastoma and requires specialist assessment to distinguish concerning from benign causes.
As tumours progress, children may develop eye redness, pain, or swelling, though these symptoms typically appear later in the disease course. Vision problems can be difficult to detect in very young children who cannot articulate what they see, making parental observation and routine health visitor checks vital for early recognition. Some children experience decreased vision in the affected eye or eyes, though infants and toddlers adapt remarkably well to visual impairment, potentially masking the underlying problem until tumours become more advanced.
In rare cases where retinoblastoma goes undetected for an extended period, tumours may grow large enough to cause visible changes to the eye's appearance or spread beyond the eye itself. However, this outcome has become increasingly uncommon in the UK due to improved awareness among healthcare professionals and better access to paediatric ophthalmology services through NHS pathways.
Video: Is cancer in your genes?
Affected organs
Retinoblastoma primarily affects the retina, the specialised tissue lining the inner surface of the eye that converts light into neural signals for vision. Tumours develop from immature retinal cells that fail to stop dividing as they should, forming masses that can involve one or multiple locations within the retina. In hereditary cases, both eyes are typically affected, though tumours may appear at different times and require individualized treatment approaches for each eye.
Beyond the immediate retinal involvement, individuals with hereditary retinoblastoma face elevated risks of developing secondary cancers throughout life, particularly osteosarcoma (bone cancer), soft tissue sarcomas, and melanoma. Research suggests that the same RB1 pathway disruption that permits retinal tumour formation also increases vulnerability to malignant transformation in other tissues, creating a lifelong need for cancer surveillance even after successful treatment of the eye tumours. The pineal gland, located deep within the brain, represents another site where tumours occasionally develop in a pattern sometimes called trilateral retinoblastoma, though this occurs relatively rarely and typically within the first few years of life.
Risks & severity
Children who inherit a pathogenic RB1 variant face approximately 90% likelihood of developing retinoblastoma, usually before their fifth birthday, with most tumours appearing by age two. The bilateral presentation typical of hereditary cases creates greater treatment complexity compared to unilateral sporadic retinoblastoma, as preserving useful vision in at least one eye while achieving cancer control becomes the primary clinical goal. Severity varies considerably depending on tumour number, location, and size at diagnosis, with some children requiring only focal treatments whilst others need more extensive interventions including chemotherapy or, in advanced cases, surgical removal of the affected eye.
Beyond the childhood retinoblastoma risk, individuals with germline RB1 variants face substantially elevated lifetime risks of developing other malignancies. Evidence suggests cumulative cancer incidence reaches approximately 50% by age 50, with osteosarcoma representing a particular concern during adolescence and young adulthood. Prior radiation therapy to treat retinoblastoma further increases subsequent cancer risk, leading modern treatment protocols to favour chemotherapy and focal approaches where feasible. These secondary cancer risks necessitate ongoing surveillance programmes extending well into adulthood, coordinated through clinical genetics services and specialist oncology teams familiar with hereditary cancer predisposition syndromes.
Genetic causes
Pathogenic variants in RB1 disrupt production or function of the retinoblastoma protein, a crucial regulator that normally acts as a brake on cell division. This protein functions by controlling when cells progress through the cell cycle, preventing premature or inappropriate proliferation. In healthy retinal development, RB1 protein ensures that immature retinal cells stop dividing at the appropriate stage and differentiate into specialised photoreceptors and other retinal cell types. When both copies of RB1 become non-functional in a retinal cell, this critical checkpoint fails, permitting unchecked cell division that leads to tumour formation.
In hereditary retinoblastoma, affected individuals inherit one non-functional RB1 copy in all their cells, meaning only one additional change (a 'second hit') in a retinal cell is needed to completely eliminate RB1 function and initiate tumour development. This explains why hereditary cases typically involve multiple tumours in both eyes - each retinal cell carrying the inherited variant has elevated probability of acquiring that second hit during the rapid cell division occurring in early eye development. The specific location and type of RB1 variant influences some aspects of disease presentation, though most pathogenic changes result in loss of functional protein and similar clinical outcomes.
Approximately 10% of children with retinoblastoma have a family history of the condition, inheriting the RB1 variant from an affected parent. However, the majority of hereditary cases arise from new (de novo) variants occurring spontaneously in the egg, sperm, or very early embryo, meaning parents typically have no family history and normal RB1 genes themselves. This pattern creates challenges for genetic counselling, as any child with bilateral retinoblastoma or unilateral disease with certain high-risk features warrants RB1 testing regardless of family history.
- RB1 RB transcriptional corepressor 1The RB1 gene provides instructions for producing the retinoblastoma protein (pRB), a crucial tumour suppressor that regulates cell growth and division, preventing uncontrolled proliferation.
Inheritance pattern
Hereditary retinoblastoma follows an autosomal dominant pattern, meaning a single pathogenic RB1 variant is sufficient to substantially increase cancer risk. Each child of an affected individual has a 50% chance of inheriting the familial RB1 variant and consequently the elevated retinoblastoma risk. However, the term 'dominant' can be somewhat misleading in this context - whilst the cancer predisposition is dominantly inherited, tumour development requires both RB1 copies in a cell to become non-functional, which occurs through a random 'second hit' during retinal development.
For families where a child develops retinoblastoma due to a new RB1 variant (rather than inheriting it from a parent), the recurrence risk for future siblings is generally low, typically quoted around 1-2% to account for the small possibility of parental germline mosaicism - where some but not all of a parent's reproductive cells carry the variant. Affected individuals themselves, however, face the 50% risk of passing the variant to each of their children. Genetic testing of apparently unaffected parents helps clarify recurrence risks and guides surveillance recommendations for siblings. Prenatal testing and preimplantation genetic diagnosis options exist for families with known RB1 variants who wish to make informed reproductive choices, though these decisions remain deeply personal and benefit from detailed discussion with clinical genetics teams.
Each child has a 50% chance of inheriting the pathogenic variant, regardless of sex.
Diagnosis & testing
Diagnosis of retinoblastoma begins with careful ophthalmological examination, often triggered by parental concern about abnormal eye appearance or observations made during routine health checks. Specialist paediatric ophthalmologists can typically identify retinal tumours through dilated eye examination, sometimes supplemented by imaging studies such as ultrasound or MRI to assess tumour extent and rule out spread beyond the eye. The appearance of retinoblastoma on examination is often distinctive enough for experienced clinicians to make the diagnosis without requiring biopsy, which carries risks of tumour spread.
Genetic testing for RB1 variants confirms hereditary status and has important implications for treatment decisions, surveillance of the affected child's other eye, screening of siblings, and future family planning. NHS Genomic Medicine Service pathways facilitate access to RB1 testing through clinical genetics services, typically initiated following retinoblastoma diagnosis or when family history raises concern. The relevant PanelApp test includes RB1 as part of R210 (Inherited retinoblastoma) and related panels. Testing usually involves blood sampling to detect germline variants, though in cases where no blood variant is found, tumour tissue analysis may reveal somatic changes that still inform treatment but carry different implications for relatives. Results typically inform not only immediate clinical management but also long-term surveillance strategies and genetic counselling for the extended family.
Management & lifestyle
Treatment for retinoblastoma aims to cure the cancer whilst preserving as much vision as possible, with approaches tailored to tumour size, location, and whether one or both eyes are affected. Modern protocols favour globe-conserving strategies where feasible, using chemotherapy (often delivered systemically or directly into the ophthalmic artery), focal treatments such as laser therapy or cryotherapy, and occasionally targeted radiation therapy. Children with very advanced disease in one eye may require enucleation (surgical eye removal) to prevent spread, though such interventions have become less common with advances in chemotherapy techniques and earlier detection.
Long-term management extends well beyond the initial retinoblastoma treatment, encompassing regular ophthalmological surveillance of any preserved eyes, monitoring for secondary cancers, and psychosocial support for children and families navigating the condition's implications. NHS care pathways typically coordinate multidisciplinary input from paediatric oncology, ophthalmology, clinical genetics, and specialist nurses. Evidence regarding lifestyle modifications remains limited, though general cancer prevention advice around sun protection, healthy diet, and avoiding tobacco applies. Some data suggest careful radiation exposure minimization where possible may reduce secondary cancer risk, influencing treatment choice when multiple options offer similar cancer control.
Families benefit from connection with specialist retinoblastoma centres that concentrate expertise and can offer access to clinical trials investigating novel approaches. Genetic counselling services help families understand inheritance patterns, recurrence risks, and testing options for relatives. Psychological support addresses the considerable emotional burden of childhood cancer diagnosis and treatment, whilst educational and social services input may assist children experiencing vision impairment resulting from the condition or its treatment.
UK care pathway
Within the NHS Genomic Medicine Service, suspected hereditary retinoblastoma triggers referral through established paediatric oncology pathways, typically coordinated via regional specialist retinoblastoma centres. Initial diagnosis usually occurs through emergency or routine ophthalmology services, prompting rapid referral to paediatric oncology teams experienced in retinoblastoma management. Genetic testing access follows through clinical genetics services, with RB1 analysis available via the R210 (Inherited retinoblastoma) testing pathway, facilitating confirmation of hereditary status and informing both treatment decisions and family screening.
Clinical genetics involvement provides comprehensive genetic counselling, helping families understand inheritance patterns, arranging predictive testing for at-risk relatives where appropriate, and discussing reproductive options for affected individuals planning families. Genetic counsellors play a vital role in explaining complex risk information, supporting decision-making around genetic testing of children and siblings, and connecting families with relevant support resources. Long-term surveillance programmes coordinated through specialist centres monitor for disease recurrence and secondary malignancies, with protocols evolving as evidence accumulates regarding optimal screening approaches for individuals with germline RB1 variants throughout their lifespan.
Frequently asked questions
If my child has hereditary retinoblastoma, will my other children develop it too?
If your affected child inherited the RB1 variant from you, each of your other children has a 50% chance of inheriting the same variant and similar cancer risk. However, if your child's RB1 variant arose newly (de novo), recurrence risk for siblings is much lower, typically 1-2%. Genetic testing of your affected child and potentially you and your partner helps clarify these risks, and siblings can be offered screening eye examinations regardless of genetic test results.
Can retinoblastoma spread to other parts of the body?
Retinoblastoma can spread beyond the eye if not treated promptly, potentially affecting nearby tissues, lymph nodes, or distant organs. However, modern UK treatment protocols achieve excellent cure rates by detecting and treating retinoblastoma early, before spread occurs. The greater long-term concern for individuals with hereditary retinoblastoma involves elevated risks of developing new, unrelated cancers later in life, which is why ongoing surveillance continues after successful retinoblastoma treatment.
Will my child lose their vision if they have retinoblastoma in both eyes?
Many children with bilateral retinoblastoma retain useful vision in at least one eye following treatment, though outcomes vary depending on tumour location and size. Modern treatment approaches prioritize vision preservation where compatible with cancer cure. Your child's ophthalmology and oncology team will discuss the balance between cancer control and vision preservation for your child's specific situation, and support services exist to help children adapt if significant vision loss occurs.
What cancer screening will my child need as they grow up?
Children treated for hereditary retinoblastoma require ongoing eye examinations to monitor for new retinal tumours, typically continuing until the risk period passes in mid-childhood. Throughout life, individuals with RB1 variants need surveillance for secondary cancers, particularly bone and soft tissue sarcomas. Your clinical genetics team will outline a personalized surveillance programme, though protocols continue evolving as research clarifies the most effective screening approaches for different age groups.
Could I have passed retinoblastoma to my child without knowing I had the gene change?
Yes, this occurs occasionally when a parent carries an RB1 variant that did not cause retinoblastoma during their own childhood, either through incomplete penetrance or because they had mild disease that resolved spontaneously and went unnoticed. Genetic testing can identify whether either parent carries the familial variant. Some parents prove to have low-level mosaicism, where only some cells carry the variant, creating the possibility of transmission without having had retinoblastoma themselves.