Ming-yan He1, Yu An, Gang Li, Jiang Qian, Yi-jin Gao. 1. Department of Hematology and Oncology, Children's Hospital of Fudan University, Shanghai 201102, P. R. China. Email: gaoyijin@hotmail.com.
Abstract
OBJECTIVE: To study the characteristics of RB1 gene mutations in Chinese patients with retinoblastoma. METHODS: Peripheral blood samples of 35 patients with retinoblastoma were collected and genomic DNA was extracted. Multiplex PCR sequencing was carried out to identify RB1 gene mutations. Parents of 6 probands with RB1 mutations were also enrolled to identify the origins of mutations. RESULTS: Fourteen patients were found to have carried germline mutations, among whom 11 had bilateral tumors and 3 had unilateral tumors. Sixteen germline mutations were identified, among which 13 were pathological, which included 5 nonsense mutations (c.1072C > T, c.1333C > T, c.1363C > T, c.1399C > T, c.2501C > A), 4 missense mutations (c.920C > T, c.1346G > A, c.1468G > A, c.1861C > A), 2 frameshift mutations (c.1947delG, c.2403delA) and 2 large fragment deletions (c.139_168 del30, exon 8 deletion). Three were non-pathological mutations, including 2 intronic mutations (c.540-23 dupT, c.2664-10T > A) and 1 silent mutation (c.2192T > A). One carrier was identified among the 6 parents of children carrying a RB1 mutation. CONCLUSION: Screening for RB1 gene mutations in patients with bilateral or unilateral retinoblastoma can help to identify heritable mutations and provide important clues for genetic counseling and clinical management.
OBJECTIVE: To study the characteristics of RB1 gene mutations in Chinese patients with retinoblastoma. METHODS: Peripheral blood samples of 35 patients with retinoblastoma were collected and genomic DNA was extracted. Multiplex PCR sequencing was carried out to identify RB1 gene mutations. Parents of 6 probands with RB1 mutations were also enrolled to identify the origins of mutations. RESULTS: Fourteen patients were found to have carried germline mutations, among whom 11 had bilateral tumors and 3 had unilateral tumors. Sixteen germline mutations were identified, among which 13 were pathological, which included 5 nonsense mutations (c.1072C > T, c.1333C > T, c.1363C > T, c.1399C > T, c.2501C > A), 4 missense mutations (c.920C > T, c.1346G > A, c.1468G > A, c.1861C > A), 2 frameshift mutations (c.1947delG, c.2403delA) and 2 large fragment deletions (c.139_168 del30, exon 8 deletion). Three were non-pathological mutations, including 2 intronic mutations (c.540-23 dupT, c.2664-10T > A) and 1 silent mutation (c.2192T > A). One carrier was identified among the 6 parents of children carrying a RB1 mutation. CONCLUSION: Screening for RB1 gene mutations in patients with bilateral or unilateral retinoblastoma can help to identify heritable mutations and provide important clues for genetic counseling and clinical management.