Difference in retinoblastoma phenotypes based on maternal or paternal inheritance
Reviewed by Lauren Hepworth

The aim of this study was to explore the difference in presentation of retinoblastoma between paternal and maternal inheritance. A retrospective medical records review methodology was employed. Records of individuals diagnosed with a retinoblastoma with at least one symptomatic family member, over a 45-year period at a single centre were reviewed. Individuals with only carrier family members and those with an unknown parent of origin were excluded. The following data was reviewed: demographics, family history, genetic testing, clinical assessment, treatment and clinical outcomes. A total of 179 individuals were identified to meet the inclusion criteria, from 136 families. Of these 61% had paternal inheritance (PI) and 39% maternal inheritance (MI). Those with PI were found to present at an older age (57 months old vs 24 months old), had more advanced classification according to the International Classification of Retinoblastoma, greater largest tumours (9mm vs 6mm), greatest tumour thickness (6mm vs 4mm), were more likely to develop retinoblastoma during follow-up (61% vs 39%) and were more likely to require enucleation (34% vs 14%). The authors acknowledge several limitations to this study including its retrospective nature, recruitment from a single site and lack of data genetics due to inclusion of individuals assessed prior to the advent of genetic testing and individuals not undergoing genetic testing. This study has presented the difference in the phenotype based on whether the genetic mutation originates from the maternal or paternal line. With future research these findings could influence clinical care including follow-up intervals.

Familial retinoblastoma: variations in clinical presentation and management based on paternal versus maternal inheritance.
Eiger-Moscovich M, Ruben M, Dockery PW, et al.
JOURNAL OF THE AMERICAN ASSOCIATION FOR PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2024;28:103804.