ABSTRACT
BACKGROUND: Retinoblastoma (MIM +180 200) is a malignant neoplasm affecting embryonal retina, associated with mutations in the RB1 gene. This paper investigates the results of RB1 testing in retinoblastoma management in a tertiary referral centre. METHODS: A retrospective audit of genetic testing for retinoblastoma from 2003 to 2008, to determine epidemiology, rate of mutation detection and spectrum was undertaken. Eligible probands were identified from the department database and hospital records examined. DNA extracted from tumour tissue and/or peripheral blood was analysed. All patients and families underwent genetic counselling. RESULTS: Twenty patients, including one family, were identified. Eight had bilateral tumours, of whom seven presented before 2 years of age, whereas 10 of 12 unilateral cases presented after 2 years of age. Ten patients (50%) were European, four Maori (20%), three Pacific (15%), two Asian (10%), and one of mixed ancestry (5%). Genetic analysis achieved mutation detection on all affected alleles of all the patients, with tumour tissue available for testing in 19 cases. Ten (40%) had germline mutations (eight bilateral and two unilateral), including one mosaic. 75% of affected Maori had germline mutations compared with 40% Europeans. A wide range of mutations was detected with one novel mutation identified in a familial case. CONCLUSION: Advances in gene testing have enabled a high rate of mutation detection, particularly when tumour tissue is genotyped. Genetic analysis is integral to the management of retinoblastoma patients allowing enhanced follow-up care, avoidance of unnecessary examinations, family screening, counselling and reproductive planning, with early tumour detection in predisposed individuals.
Subject(s)
Mutation , Retinal Neoplasms/genetics , Retinoblastoma/genetics , Age of Onset , Child , Chromosome Mapping , Chromosomes, Human, Pair 13 , Exons/genetics , Female , Genes, Retinoblastoma , Genetic Testing/methods , Humans , Incidence , Infant , Infant, Newborn , Male , New Zealand/epidemiology , Retinal Neoplasms/epidemiology , Retinal Neoplasms/therapy , Retinoblastoma/epidemiology , Retinoblastoma/therapy , Retinoblastoma Protein/blood , Retinoblastoma Protein/geneticsABSTRACT
A diagnosis of retinoblastoma is devastating not only for the parents of the children but also for the ophthalmic staff who are involved in the provision of care. In Auckland, New Zealand, the Ophthalmology Department provides specialist ophthalmic care for children and their families diagnosed with retinoblastoma. It became clear to nurses with an interest in retinoblastoma that the service provided was not meeting the needs of patients and families, particularly since the numbers had increased over the past two years. Improving our service was essential, but it had to be done in a cost-effective way. We have been successful in implementing a dedicated support network and service for these patients and families with very little additional resources, and we are extremely proud of these achievements.
