Researchers lead first major genetic study on retinoblastoma in Kenya

A pioneering international study led by scientists at The Hospital for Sick Children (SickKids) and the University of Nairobi is investigating the genetic factors driving retinoblastoma — the most common eye cancer in children — in Kenyan patients.  

Retinoblastoma affects infants and young children, targeting the retina due to variants in the RB1 gene. These variants may either be inherited or develop spontaneously. While cancer genetics research has advanced in high-income countries globally, African countries have remained largely overlooked.  

In a recently published commentary in Nature Genetics, the research team describes the first large-scale effort to examine genetic factors in Kenyan children diagnosed with retinoblastoma. Led by Dr. Helen Dimaras, Director of Global Eye Health Research and Scientist at the SickKids Centre for Global Child Health, and Dr. Lucy Njambi, Lecturer in the Department of Ophthalmology at the University of Nairobi, the study will analyze blood and tumour samples from approximately 300 children with retinoblastoma across Kenya over the four-year project period, from 2023 to 2027. 

“Identifying genetic variants in the Kenyan population through this research will help us understand the mutation profile and how patients may respond to current treatments,” says Njambi. “Genetic testing also opens up the possibility for earlier diagnosis and more effective treatment, improving outcomes for family members who may carry the variant.” 

Improving diagnosis and treatment for children 

In Kenya, genetic testing for retinoblastoma is not widely available, leading to unnecessary hospital visits for some children who may not need additional treatment.  

“Genetic testing can confirm whether a pathogenic variant is carried by the individual with retinoblastoma, removing the need for repeated screening for new tumours,” says Dimaras, Scientist in the Child Health Evaluative Sciences program at SickKids. “If an individual carries a pathogenic variant, we can also inform them they are at risk for second cancers later in life and that future generations may also be affected.” 

Currently, without genetic testing, families are often given conservative counselling, assuming the presence of hereditary retinoblastoma. Testing would not only offer peace of mind but, over time, reduce health-care costs for many families. 

Building Kenya’s capacity for genetic testing and research 

As the first initiative of its kind in East Africa, this study is a major milestone in expanding cancer genetics research in low- and middle-income countries and will provide Kenyan health-care providers with critical local genetic insights to better serve their communities. 

The authors note the findings from this research may also uncover a distinct molecular profile in Kenyan patients that has not been previously documented, potentially contributing to global cancer genetics research and promoting equity in genetic services. 

“The retinoblastoma gene has not been studied very robustly in any African population,” says Dimaras. “We may identify biomarkers that contribute to the advanced stages of retinoblastoma, which is more common in Kenya.” 

In collaboration with SickKids and the University of Toronto, the University of Nairobi is further embedding genetic research capabilities within the Kenyan health-care system by advancing gene sequencing and biobanking infrastructure. 

Njambi notes: "Our work not only advances genetic research but also trains the next generation of experts here in Nairobi to make future discoveries. We’re also listening to parents' experiences with genetic testing and counselling, insights that will help shape the future of clinical services across Kenya." 

This research is supported by the Velux Stiftung ophthalmology grant program.