Recent advances in retinoblastoma genetic research

Brain MRI Screening for Bilateral Retinoblastoma Patients

PURPOSE

Trilateral retinoblastoma (TRB), intracranial neoplasm in heritable retinoblastoma patients, is a very rare fatal disease. Many ocular oncology centers conduct routine screening of retinoblastoma patients by brain imaging. Nevertheless, there is a debate regarding its ability to prolong TRB patients' survival and the number-needed-to-treat. We recommend baseline screening brain imaging in bilateral retinoblastoma patients, followed by imaging according to clinical need. We aim to see if this screening schedule has an impact on patients' survival.

METHODS

In a retrospective observational study, we reviewed the medical records of patients diagnosed with bilateral retinoblastoma at a tertiary medical center ocular oncology unit between 1.7.1986 and 1.2.2020, who had at least 36 months follow-up or retinoblastoma-related death. We collected data on patients' demographics, clinical features, systemic evaluation, treatment, follow-up, and outcome.

RESULTS

The analysis included 109 patients, 60 males and 49 females, diagnosed with bilateral retinoblastoma at a median age of 7.0 months (range 0.43-70.5 months). Germline mutation was found in 43 patients (39.4%) and somatic mutation in 15 patients (13.8%). Genetic status was not recorded in 51 patients (46.8%). Fifty-eight patients (53.0%) underwent baseline brain imaging (MRI in 42 patients and CT scan in 16 patients), in all of whom it was within normal limits. During a median follow-up of 138 months (range 19-787 months), 35 children had follow-up brain imaging (MRI in 25 patients and CT in 10 patients). One patient developed symptomatic TRB during follow-up, and is alive and disease-free (0.9%, Cl:0.02%-5.6%). Looking at survival, six patients (5.5%) developed metastatic disease, and eight patients (7.3%) expired, in all of whom death was retinoblastoma-related.

CONCLUSIONS

Due to TRB rarity, routine screening by baseline brain MRI may be sufficient, avoiding anesthesia, expenses, distress, and unnecessary interventions, without a significant impact on patients' survival. Nevertheless, due to TRB fatality and treatment morbidity, periodic brain MRI until age 3 is a legitimate option.

Epidemiology, Diagnosis and Genetics of Retinoblastoma: ICMR Consensus Guidelines

Retinoblastoma (RB) is the most common intraocular tumor in childhood. It is mainly caused by mutations in both alleles of the RB1 tumor suppressor gene that is found on chromosome 13 and regulates the cell cycle. Approximately 8000 children are diagnosed with RB globally each year, with an estimated 1500 cases occurring in India. The survival rate of RB has improved to more than 90% in the developed world. Leukocoria and proptosis are the most common presenting features of RB in Asian Indian populations. Most cases of RB are diagnosed by fundus examination followed by ultrasound. The International Classification of Retinoblastoma is the most used scheme for the staging and classification of intraocular RB in India. Prenatal testing and preimplantation genetic testing for RB may be beneficial in high-risk families. Histopathologic risk factors such as massive choroidal invasion and post-laminar optic nerve help in predicting the occurrence of metastasis in children with RB, while presence of microscopic residual disease requires aggressive adjuvant treatment in eyes enucleated for group E RB. The review provides a consensus document on diagnosis and genetics of RB in India.

Serum Metabolomics of Retinoblastoma: Assessing the Differential Serum Metabolic Signatures of Unilateral and Bilateral Patients

Retinoblastoma (Rb) is the most common pediatric eye cancer. To identify the biomarkers for early diagnosis and monitoring the progression of Rb in patients, mapping of the alterations in their metabolic profiles is essential. The present study aims at exploring the metabolic disparity in serum from Rb patients and controls using NMR-based metabolomics. A total of 72 metabolites, including carbohydrates, amino acids, and organic acids, were quantified in serum samples from 24 Rb patients and 26 controls. Distinct clusters of Rb patients and controls were obtained using the partial least-squares discriminant analysis (PLS-DA) model. Further, univariate and multivariate analyses of unilateral and bilateral Rb patients with respect to their age-matched controls depicted their distinct metabolic fingerprints. Metabolites including 2-phosphoglycerate, 4-aminobutyrate, proline, O-phosphocholine, O-phosphoethanolamine, and Sn-glycero-3-phosphocholine (Sn-GPC) showed significant perturbation in both unilateral and bilateral Rb patients. However, metabolic differences among the bilateral Rb cases were more pronounced than those in unilateral Rb cases with respect to controls. In addition to major discriminatory metabolites for Rb, unilateral and bilateral Rb cases showed specific metabolic changes, which might be the result of their differential genetic/somatic mutational backgrounds. This further suggests that the aberrant metabolic perturbation in bilateral patients signifies the severity of the disease in Rb patients. The present study demonstrated that identified serum metabolites have potential to serve as a noninvasive method for detection of Rb, discriminate bilateral from unilateral Rb patients, and aid in better understanding of the RB tumor biology.

Retinoblastoma: emerging concepts in genetics, global disease burden, chemotherapy outcomes, and psychological impact

In this review we discuss several recent concepts regarding retinoblastoma control and its impact. In a cohort of 482 patients with solitary unilateral retinoblastoma revealed germline mutation in 16% and the likelihood of germline retinoblastoma was greater for younger children (≤1 year versus (vs.) >1 year at presentation) with odds ratio (OR) 2.96 (p = 0.001), and greatest for the youngest infants (≤3 months vs. >3-12 months) (OR 5.52) (p = 0.002). Retinocytoma/retinoma, a benign variant of retinoblastoma, was studied in 78 tumours and demonstrated transformation into retinoblastoma in 9.2% by 5 years and 15.3% by 10 years and 20 years. An international global study on retinoblastoma over 1.5 years revealed 4351 new patients and 85% from low- and middle-income countries, notably with older age at detection and greater risk for metastasis. Management of retinoblastoma in 964 eyes using intravenous chemotherapy showed 20-year globe salvage at 96% in group A, 90% in group B, 90% in group C, 68% in group D, and 32% in group E eyes. The 5-year globe salvage with intra-arterial chemotherapy for 160 eyes (655 infusions) with retinoblastoma showed success in 100% for group B, 80% for group C, 78% for group D, and 55% for group E. The psychological impact of retinoblastoma on the parents revealed depression (73%), anxiety (64%), and/or stress (100%), and on the patient revealed deficits in quality of life issues. Retinoblastoma is a challenging disease and chemotherapy provides reliable tumour control and globe salvage. Continuing efforts to improve quality of life issues is important.

Likelihood of Germline Mutation With Solitary Unilateral Retinoblastoma Based on Patient Age at Presentation: Analysis of 482 Consecutive Patients

PURPOSE

To evaluate the likelihood of germline retinoblastoma in patients presenting with solitary unilateral retinoblastoma, based on age at presentation.

METHODS

This retrospective case series of 482 consecutive patients presenting with solitary unilateral retinoblastoma analyzed the likelihood of germline retinoblastoma, defined as family history of retinoblastoma, germline retinoblastoma mutation documented on genetic testing, and/or development of bilateral disease and/or additional new tumors. This analysis was based on age at presentation (0 to 12 months vs older than 12 to 24 months vs older than 24 to 36 months vs older than 36 months) and a sub-study was conducted on infant age at presentation (0 to 3 months vs older than 3 to 6 months vs older than 6 to 9 months vs older than 9 to 12 months).

RESULTS

Of the overall group (482 consecutive patients) with solitary unilateral retinoblastoma, there were significantly different findings in the youngest age group (0 to 12 months old) with greater family history of retinoblastoma (10% vs 2% vs 1% vs 2%, P = .004), smaller median basal diameter (18.0 vs 20.0 vs 20.0 vs 20.0 mm, P = .014), smaller median tumor thickness (8.7 vs 10.0 vs 11.5 vs 10.0 mm, P = .002), greater macular tumor location (33% vs 16% vs 10% vs 8%, P < .001), and greatest likelihood of germline mutation (29% vs 17% vs 8% vs 9%, P = .001). By comparison, patients 1 year and younger (vs older than 1 year) demonstrated a 2.96 odds ratio (OR) (P = .001) for likelihood of germline retinoblastoma. For those classified as infants (1 year and younger) (n = 132 consecutive patients), the youngest patients (0 to 3 months old) demonstrated the greatest likelihood for germline mutation (61% vs 20% vs 24% vs 22%, P = .009) and greatest odds ratio (5.52, P = .002) compared to patients older than 3 to 12 months.

CONCLUSIONS

The youngest patients with solitary unilateral retinoblastoma showed the greatest likelihood of germline disease when evaluating all patients (1 year and younger vs older than 1 year of age) (OR = 2.96) and the substudy of infants (3 years and younger vs older than 3 to 12 months old) (OR = 5.52). [J Pediatr Ophthalmol Strabismus. 2021;58(6):355-364.].

miR-340 Exerts Suppressive Effect on Retinoblastoma Progression by Targeting KIF14

Purpose: This work aimed to investigate the influences of microRNA-340 (miR-340) on proliferation and apoptosis of retinoblastoma (RB) cells and explore its regulatory mechanism.

MATERIALS AND METHODS

miR-340 mimic and inhibitor were applied for up-regulating or inhibiting the expression of miR-340 in RB cell lines. Then, CCK-8 and AnnexinV-FITC/PI staining were used to measure cell proliferation and apoptosis, respectively. After that, luciferase assay was performed to affirm the direct targets of miR-340. Furthermore, qRT-PCR and western blotting assay were carried out to detect the levels of miR-340 and KIF14.

RESULTS

Our results indicated that the miR-340 was lowly expressed in RB cell lines, and up-regulation of miR-340 can decrease the proliferation and induce the apoptosis of RB cells. Moreover, we verified that miR-340 controls KIF14 expression, either directly or through a subsequent molecular cascade, and inversely related to its expression. The results obtained from the rescue assays presented that over-expression of KIF14 reversed the miR-340-mediated inhibition on malignant phenotype of RB cells.

CONCLUSIONS

Overall, we proved that miR-340 can decrease the proliferation and increase the apoptosis of RB cells, and its function in RB cells was at least partially achieved via down-regulation of KIF14, prompting that miR-340 was expected to supply a new direction for clinical therapy of RB in the future.

The Role of Intraarterial Chemotherapy in the Management of Retinoblastoma

Introduction. Retinoblastoma is the most common primary intraocular neoplasm in children. With the advances in medicine, the armamentarium of available treatment modalities has grown. Intraarterial chemotherapy is a relatively new treatment method with promising outcomes. The purpose of this literature review is to evaluate its role in the management of retinoblastoma.

Retinoblastoma

Retinoblastoma represents 3% of all childhood cancers, and is the most common intraocular malignancy of childhood. It is fatal, if untreated. White eye reflex, also known as leukocoria, is the commonest sign, followed by strabismus. The pediatricians have a very important role to play in the diagnosis of this relatively rare, but easily detectable tumor. Early diagnosis yields better results. The management of retinoblastoma has gradually evolved over the past few decades, with an aim to not only preserve life and eye, but also optimize residual vision. The treatment of retinoblastoma is multimodal, with chemotherapy, focal treatment including trans-pupillary thermotherapy, cryotherapy and laser photocoagulation, radiation therapy and surgery, all playing a vital role. Intravenous chemotherapy has been the mainstay of treatment for the past two decades, and still continues to be the most extensively used eye-saving modality of treatment. Periocular and intravitreal chemotherapy have specific indications in the management of retinoblastoma. Intra-arterial chemotherapy has emerged as a promising alternative for advanced and refractory retinoblastoma, both as a primary and secondary therapy. Recent advances in genetics of retinoblastoma have also helped in improving the overall clinical management of this malignancy.

An optimized gene transfection system in WERI-Rb1 cells

The pathogenesis of Rb1 gene inactivation indicates that gene therapy could be a promising treatment for retinoblastoma. An appropriate gene transfer system is the basis for successful gene therapy; however, little attention has been given to an effective gene transfer system for retinoblastoma therapy in previous studies. This study was designed to provide an optimized transgene system for WERI-Rb1 cells (W-RBCs). Green fluorescent protein (GFP) was adopted as a reporter. Four classic viral vectors based on retroviruses, recombinant adeno-associated viruses (rAAV2, rAAV2/1), lentiviruses (LVs) and a novel non-viral vector X-treme HP reagent were adopted for W-RBC gene transfection. The efficacy and cytotoxicity were comprehensively compared among the different vectors through GFP expression and the trypan blue exclusion test. Furthermore, the serum and cell culture status were also optimized for better transfection. Cells transfected by rAAV2/1 expressed more GFP protein and exhibited less staining with trypan blue, compared to the rAAV2 counterpart. However, in comparison to the retroviral group, both the rAAV2/1 and LV groups had considerably less GFP⁺ cells. Interestingly, the X-treme HP presented a similar GFP transfection capacity to the retroviral vector, but with a much lower cytotoxicity. Furthermore, there were more GFP⁺ cells in a suspended condition than that in an adherent culture. Moreover, cells in a serum-positive system expressed more GFP, while cells in a serum-free system showed lower GFP expression and higher cytotoxicity. In conclusion, the retroviral vector and the X-treme HP are effective for W-RBC gene transfection, while the X-treme HP is more preferable due to its lower cytotoxicity. Moreover, the suspended cell culture system is superior to the adherent system, and the serum protects cell viability and facilitates the gene transfection of W-RBCs. This study presents an effective, convenient, and low toxic transfection system for gene delivery in W-RBCs and provides a promising system for further gene therapy of retinoblastoma.

Genetic screening in patients with Retinoblastoma in Israel

Retinoblastoma (Rb) is a childhood tumor (~1 in 20,000 live births) developing in the retina due to mutations in the RB1 gene. Identification of the oncogenic mutations in the RB1 gene is important for the clinical management and for genetic counseling to families with a child or a parent affected with the tumor. Here we present our experience in detecting the pathogenic mutations in blood samples, from 150 unrelated Rb patients and highlight the relevant counseling issues. Mutation screening in the RB1 gene was based on Sanger sequencing, mosaicism of recurrent CpG transition mutations was detected by allele specific PCR and multiplex ligation dependent probe amplification for detecting of large deletions/duplications. The overall detection rate of mutations in our cohort was 55% (82/150). In the familial cases it was 100% (17/17), in bilateral and unilateral-multifocal sporadic cases 91% (50/55), and in the unilateral sporadic cases 19% (15/78). Nonsense mutations and small deletions or insertions that results in transcripts with premature termination codons that are subject to nonsense mediated decay were the most frequent, detected in 50/82 (61%) of the patients. The rest were large deletions detected in 14/82 (17%), splice site mutations detected in 11/82 (13%), missense mutations in four patients and mutations in the promoter sequence in three patients. Mutation mosaicism ranging from 10 to 30% was detected by allele specific PCR in ten patients, 9% (5/55) of patients with bilateral tumor and 33% (5/15) of the patients with unilateral tumor. In three patients rare variants were detected as the only finding which was also detected in other healthy family members. Allele specific amplification of recurrent mutations raises in our cohort the identification rate from 82 to 91% in the sporadic bilateral cases and from 13 to 19% in the unilateral sporadic cases. Most mosaic cases could not be identified by Sanger sequencing and therefore screening for recurrent CpG transition mutations by allele specific amplification is of utmost importance. Molecular screening is important for the genetic counseling regarding the risk for tumor development and the relevance for prenatal diagnosis but in several families is accompanied by detecting rare variants that might be rare polymorphisms or low penetrant mutations.

Maternal diet during pregnancy and unilateral retinoblastoma

PURPOSE

Previous studies have suggested a role for parental diet in childhood cancer prevention, but there are few studies of retinoblastoma. The aim of this study was to examine the relation between maternal diet and unilateral retinoblastoma.

METHODS

A case-control study of 163 unilateral RB cases and 136 controls ascertained information on maternal diet during pregnancy using a standardized food frequency questionnaire. Logistic regression was used to assess the relation between retinoblastoma and food groups and dietary patterns.

RESULTS

We observed a negative association between retinoblastoma and intake of fruit [odds ratio (OR) 0.38, 95 % confidence interval (CI) 0.14-1.02]. Positive associations were seen with intake of cured meats (OR 5.07, 95 % CI 1.63-15.70) and fried foods (OR 4.89, 95 % CI 1.72-13.89). A food pattern of high fruits and vegetables and low fried food and sweets was negatively associated with disease (OR 0.75, 95 % CI 0.61-0.92).

CONCLUSION

Our study provides preliminary evidence that mothers who consume diets higher in fruit and lower in fried foods and cured meats during pregnancy may reduce the risk of unilateral retinoblastoma in their offspring.

Enhanced sensitivity for detection of low-level germline mosaic RB1 mutations in sporadic retinoblastoma cases using deep semiconductor sequencing

Sporadic retinoblastoma (RB) is caused by de novo mutations in the RB1 gene. Often, these mutations are present as mosaic mutations that cannot be detected by Sanger sequencing. Next-generation deep sequencing allows unambiguous detection of the mosaic mutations in lymphocyte DNA. Deep sequencing of the RB1 gene on lymphocyte DNA from 20 bilateral and 70 unilateral RB cases was performed, where Sanger sequencing excluded the presence of mutations. The individual exons of the RB1 gene from each sample were amplified, pooled, ligated to barcoded adapters, and sequenced using semiconductor sequencing on an Ion Torrent Personal Genome Machine. Six low-level mosaic mutations were identified in bilateral RB and four in unilateral RB cases. The incidence of low-level mosaic mutation was estimated to be 30% and 6%, respectively, in sporadic bilateral and unilateral RB cases, previously classified as mutation negative. The frequency of point mutations detectable in lymphocyte DNA increased from 96% to 97% for bilateral RB and from 13% to 18% for unilateral RB. The use of deep sequencing technology increased the sensitivity of the detection of low-level germline mosaic mutations in the RB1 gene. This finding has significant implications for improved clinical diagnosis, genetic counseling, surveillance, and management of RB.

Combined chemotherapy and intra-arterial chemotherapy of retinoblastoma

Purpose

Retinoblastoma (RB) is the most common primary malignant intraocular tumor in children. Although systemic chemotherapy has been the primary treatment, intra-arterial chemotherapy (IAC) represents a new treatment option. Here, we performed alternate systemic chemotherapy and IAC and retrospectively reviewed the efficacy and safety of this approach.

Methods

Patients diagnosed with intraocular RB between January 2000 and December 2011 at Severance Children's Hospital, Yonsei University, were reviewed. Before February 2010, the primary treatment for RB was chemotherapy (non-IAC/CTX). Since February 2010, the primary treatment for RB has been IAC (IAC/CTX). External beam radiotherapy or high-dose chemotherapy were used as "last resort" treatments just prior to enucleation at the time of progression or recurrence during primary treatment. Enucleation-free survival (EFS) and progression-free survival were assessed.

Results

We examined 19 patients (median age, 11.9 months; range, 1.4 to 75.6 months) with a sum of 25 eyes, of which, 60.0% were at advanced Reese Ellsworth (RE) stages. The enucleation rate was 33.3% at early RE stages and 81.8% at advanced RE stages (P=0.028). At 36 months, EFS was significantly higher in the IAC/CTX group than in the non-IAC/CTX group (100% vs. 40.0%, P=0.016). All 5 patients treated with IAC achieved eye preservation, although most patients were at advanced RE stages (IV-V).

Conclusion

Despite the limitation of a small sample size, our work shows that an alternative combined approach using IAC and CTX may be safe and effective for eye preservation in advanced RB.

Retinoblastoma: Recent trends A mini review based on published literature

Retinoblastoma (RB) is the most common intraocular malignancy in children. Recently, there have been significant advances made in the molecular pathology and the management of the disease. Last decade has witnessed better understanding of the genetics of RB, the discovery of new tumor markers expressed by the RB tumors, the identification of high-risk histopathological factors following enucleation, and newer methods of treatment including periocular chemotherapy and superselective intraarterial chemotherapy. All these advances have translated in improved survival rates for the affected children, improved rates of eye salvage, and improved visual outcomes. This article briefly reviews these advances.Method of Literature Search: Literature on the Medline database was searched using the PubMed interface. The search strategy included MeSH and natural language terms using the keywords mentioned. Reference lists in retrieved articles and textbooks were also searched for relevant references.

We contain multitudes: the protean face of retinoblastoma

The precise cellular characteristics of retinoblastoma have long been debated. In this issue of Cancer Cell, McEvoy et al. reveal that retinoblastomas are highly homogeneous at the molecular level and coexpress genes characteristic of retinal progenitors and various different mature retinal cell types, while ultrastructurally resembling amacrine cells.

Epidemiology and Rb1 gene of retinoblastoma

Retinoblastoma (Rb) is the most common eye cancer in children and it can be inherited. Rb is quite rare and originators from the neural retina with a significant genetic component in etiology, which occurs in approximately 1 in every 20 0000 births. In children with the heritable genetic form of Rb, there is a mutation on chromosome 13, called the retinoblastoma 1 (Rb1) gene. Early diagnosis and intervention is critical to the successful treatment of the Rb. The Rb1 gene is the first cloned tumor suppressor gene. As a negative regulator of the cell cycle, Rb1 gene could maintain a balance between cell growth and development through binding to transcription factors and regulating the expression of genes involved in cell proliferation and differentiation. Thus, it is involved in cell cycle, cell senescence, growth arrest, apoptosis and differentiation. We summarized the recent advances on the epidemiology and Rb1 gene of Rb in this review.

Vascular Recruitment of Human Retinoblastoma Cells by Multi-Cellular Adhesive Interactions with Circulating Leukocytes

Retinoblastoma (RB) is a retinal cancer of childhood. RB survivors tend to develop additional tumors later in life, although the physical mechanisms of RB metastatic spread are largely unknown. One step in metastasis through the blood stream is tumor cell adherence to the blood vessel wall through specific receptor:ligand interactions. Yet, human RB cell lines RB143 and WERI-Rb27 do not express selectin ligands or beta-2 integrins and cannot directly interact with inflamed endothelium. In this study, we show that RB cells express ICAM-1, a beta-2 integrin ligand that correlates with metastasis and is preferentially co-expressed on RB cells that also express ABCG2, a stem cell marker associated with chemoresistance and metastasis. Based on the presence of ICAM-1+ RB cells, we tested the hypothesis that RB cells could be recruited to an E-selectin surface via attachment to activated polymorphonuclear cells (PMNs). We characterized the dynamic adhesion between RB cells and PMNs within E-selectin coated microtubes under a physiological range of wall shear stress values (0.2-5 dyn/cm²). We show that activated PMNs are necessary for the recruitment of RB cells through ICAM-1:LFA-1 binding. Results from this work may lead to new strategies that target the metastatic spread of tumor cells.

Disruption of the ATP8A2 gene in a patient with a t(10;13) de novo balanced translocation and a severe neurological phenotype

Mental retardation is a frequent condition that is clinically and genetically highly heterogeneous. One of the strategies used to identify new causative genes is to take advantage of balanced chromosomal rearrangements in affected patients. We characterized a de novo t(10;13) balanced translocation in a patient with severe mental retardation and major hypotonia. We found that the balanced translocation is molecularly balanced. The translocation breakpoint disrupts the coding sequence of a single gene, called ATP8A2. The ATP8A2 gene is not ubiquitously expressed, but it is highly expressed in the brain. In situ hybridization performed in mouse embryos at different stages of development with the mouse homologue confirms this observation. A total of 38 patients with a similar phenotype were screened for mutations in the ATP8A2 gene but no mutations were found. The balanced translocation identified in this patient disrupts a single candidate gene highly expressed in the brain. Although this chromosomal rearrangement could be the cause of the severe phenotype of the patient, we were not able to identify additional cases. Extensive screening in the mentally retarded population will be needed to determine if ATP8A2 haploinsufficiency or dysfunction causes a neurological phenotype in humans.

Genome-wide microarray evidence that 8-cell human blastomeres over-express cell cycle drivers and under-express checkpoints

PURPOSE

To understand cell cycle controls in the 8-Cell human blastomere.

METHODS

Data from whole human genome (43,377 elements) microarray analyses of RNAs from normal 8-Cell human embryos were compiled with published microarrays of RNAs from human fibroblasts, before and after induced pluripotency, and embryonic stem cells. A sub database of 3,803 genes identified by high throughput RNA knock-down studies, plus genes that oscillate in human cells, was analyzed.

RESULTS

Thirty-five genes over-detected at least 7-fold specifically on the 8-Cell arrays were enriched for cell cycle drivers and for proteins that stabilize chromosome cohesion and spindle attachment and limit DNA and centrosome replication to once per cycle.

CONCLUSIONS

These results indicate that 8-cell human blastomere cleavage is guided by cyclic over-expression of key proteins, rather than canonical checkpoints, leading to rapidly increasing gene copy number and a susceptibility to chromosome and cytokinesis mishaps, well-noted characteristics of preimplantation human embryos.

Unilateral retinoblastoma in an eye with Peters anomaly

Retinoblastoma and Peters anomaly are presumably unrelated ocular conditions, although other congenital ocular anomalies have been described in association with retinoblastoma. We report the case of a neonate who presented with unilateral retinoblastoma and Peters anomaly. Retinoblastoma arises from a deregulation of cellular events secondary to inactivation of both RB1 gene alleles, whereas Peters anomaly has been linked to eye-development genes and chromosomal anomalies. A second locus for retinoblastoma, RBL2, which encodes the p130 protein, has been shown to contribute to retinoblastoma oncogenesis. Coincidentally, p130 also plays a role in corneal cell differentiation. Although the association of retinoblastoma and Peters anomaly in this patient may be coincidental, it raises the question of whether the RBL2 mutation contributed to both conditions.