Retinoblastoma and the genetic theory of cancer: an old paradigm trying to survive to the evidence

Molecular Biological Research on the Pathogenic Mechanism of Retinoblastoma

Retinoblastoma (RB) is the most common intraocular malignant tumor in children, primarily attributed to the bi-allelic loss of the RB1 gene in the developing retina. Despite significant progress in understanding the basic pathogenesis of RB, comprehensively unravelling the intricate network of genetics and epigenetics underlying RB tumorigenesis remains a major challenge. Conventional clinical treatment options are limited, and despite the continuous identification of genetic loci associated with cancer pathogenesis, the development of targeted therapies lags behind. This review focuses on the reported genomic and epigenomic alterations in retinoblastoma, summarizing potential therapeutic targets for RB and providing insights for research into targeted therapies.

13q deletion syndrome and retinoblastoma in identical dichorionic diamniotic monozygotic twins

PURPOSE

To report the case of identical dichorionic diamniotic female twins with unilateral retinoblastoma in 13q deletion syndrome.

METHODS

Clinical and ophthalmoscopic evaluation, combination of multiple ligation-dependent probe amplification, array-comparative genomic hybridization analyses, and magnetic resonance imaging were performed.

RESULTS

Peculiar facial features, marked hypotonia, gastroesophageal reflux, interatrial septal defect with left to right shunt and light dilatation of right chambers, 5th finger hypoplasia, 3rd-5th toes clinodactyly, 2nd toe overlapped to 3rd toe, and cutis marmorata were found. Ophthalmoscopic evaluation revealed unilateral retinoblastoma in both girls. Magnetic resonance imaging detected corpus callosum hypoplasia in both twins. A 34.4-Mb deletion involving bands 13q13.2-q21.33 and including the RB1 gene was identified in both twins. The deletion was not present in the DNA of their parents and older brother.

CONCLUSIONS

Dysmorphic features in children must be always suspicious of 13q deletion syndrome and a short ophthalmoscopic follow-up is necessary to detect the presence of a retinoblastoma.