Philippine retinoblastoma initiative multi-eye center study 2010-2020.

AIM: To provide a comprehensive and more representative national data on the disease, especially on treatment options and outcomes, and to determine access of retinoblastoma patients from Luzon, Visayas and Mindanao to eye care, and determine if access is associated with delay in consultation, staging and outcomes. METHODS: Cohort study of retinoblastoma patients seen in eleven institutions located in the three major areas of the Philippines namely Luzon, Vizayas and Mindanao from 2010-2020. RESULTS: Totally 636 patients, involving 821 eyes, were included. Majority (57%) were from Luzon and were seen in institutions in Luzon (72%). Annually, 58±10 new cases were seen with 71% having unilateral disease. Median delay of consultation remained long at 9 (3, 17)mo, longest in patients with unilateral disease (P<0.02) and those from the Visayas (P<0.003). Based on the International Retinoblastoma Staging System, only 35% of patients had Stage 1 while 47% already had extraocular disease. Enucleation was the most common treatment received by 484 patients while intravenous chemotherapy was received by 469. There were 250 (39%) patients alive, 195 (31%) dead, 85 (13%) abandoned, 17 (3%) refused and 89 (14%) with no data. CONCLUSION: This study presents the largest cohort of retinoblastoma patients in the Philippines in terms of patients' and participating institutions' number and geographical location and type of institution (private and public). It also presents more comprehensive data on the treatments used and outcomes (survival, globe salvage, and vision retention rates). Delay in consultation was still long among patients leading to advanced disease stage and lower survival rate. Despite increasing capacity to diagnose and manage retinoblastoma in the country, the delay of consultation remains long primarily due to accessibility issues to eye care institutions especially in the Visayas and financial concerns. The delay was still significant that overall survival rate remain low.

Molecular Genetic Analysis of Pakistani Families With Autosomal Recessive Congenital Cataracts by Homozygosity Screening.

Purpose: To identify the genetic origins of autosomal recessive congenital cataracts (arCC) in the Pakistani population. Methods: Based on the hypothesis that most arCC patients in consanguineous families in the Punjab areas of Pakistan should be homozygous for causative mutations, affected individuals were screened for homozygosity of nearby highly informative microsatellite markers and then screened for pathogenic mutations by DNA sequencing. A total of 83 unmapped consanguineous families were screened for mutations in 33 known candidate genes. Results: Patients in 32 arCC families were homozygous for markers near at least 1 of the 33 known CC genes. Sequencing the included genes revealed homozygous cosegregating sequence changes in 10 families, 2 of which had the same variation. These included five missense, one nonsense, two frame shift, and one splice site mutations, eight of which were novel, in EPHA2, FOXE3, FYCO1, TDRD7, MIP, GALK1, and CRYBA4. Conclusions: The above results confirm the usefulness of homozygosity mapping for identifying genetic defects underlying autosomal recessive disorders in consanguineous families. In our ongoing study of arCC in Pakistan, including 83 arCC families that underwent homozygosity mapping, 3 mapped using genome-wide linkage analysis in unpublished data, and 30 previously reported families, mutations were detected in approximately 37.1% (43/116) of all families studied, suggesting that additional genes might be responsible in the remaining families. The most commonly mutated gene was FYCO1 (14%), followed by CRYBB3 (5.2%), GALK1 (3.5%), and EPHA2 (2.6%). This provides the first comprehensive description of the genetic architecture of arCC in the Pakistani population.

Homozygosity Mapping and Genetic Analysis of Autosomal Recessive Retinal Dystrophies in 144 Consanguineous Pakistani Families.

Purpose: The Pakistan Punjab population has been a rich source for identifying genes causing or contributing to autosomal recessive retinal degenerations (arRD). This study was carried out to delineate the genetic architecture of arRD in the Pakistani population. Methods: The genetic origin of arRD in a total of 144 families selected only for having consanguineous marriages and multiple members affected with arRD was examined. Of these, causative mutations had been identified in 62 families while only the locus had been identified for an additional 15. The remaining 67 families were subjected to homozygosity exclusion mapping by screening of closely flanking microsatellite markers at 180 known candidate genes/loci followed by sequencing of the candidate gene for pathogenic changes. Results: Of these 67 families subjected to homozygosity mapping, 38 showed homozygosity for at least one of the 180 regions, and sequencing of the corresponding genes showed homozygous cosegregating mutations in 27 families. Overall, mutations were detected in approximately 61.8 % (89/144) of arRD families tested, with another 10.4% (15/144) being mapped to a locus but without a gene identified. Conclusions: These results suggest the involvement of unmapped novel genes in the remaining 27.8% (40/144) of families. In addition, this study demonstrates that homozygosity mapping remains a powerful tool for identifying the genetic defect underlying genetically heterogeneous arRD disorders in consanguineous marriages for both research and clinical applications.