ObjectiveTo identify the pathogenic mutation in a three generation Chinese family with low penetrance retinoblastoma (RB). Methods8 from 9 family members received complete ophthalmic examinations. DNA was extracted from 6 family members. Using exon combined target region capture sequencing chip to screen the candidate disease-causing mutations. Sanger sequencing were used to confirm the disease-causing mutation. ResultsAmong 9 family members, the proband (Ⅲ2) was bilateral RB, Ⅲ1 was unilateral RB, Ⅲ3 was dead for bilateral RB. Normal fundus were observed in the left eye ofⅢ1 and the eyes of other family members except the proband. Sequence analysis of RB1 gene revealed a missense mutation c.1981C > T (p.Arg661Trp) in the proband and two carriers (Ⅱ2, Ⅱ3), but not in the two normal subjects (Ⅱ1, Ⅱ4). We suspect that the RB penetrance in the family was 50%. ConclusionsThere is a missense mutation c.1981C > T in a Chinese family with low penetrance RB. The RB penetrance is 50%.
ObjectiveTo observe the application value of RetCam Ⅲ in the diagnosis of retinoblastoma (RB). MethodsThe clinical data of 125 eyes from 94 patients with RB were retrospectively analyzed. According to the International Intraocular Retinoblastoma Classification, the results of binocular indirect ophthalmoscope and RetCam Ⅲ was compared. The consistency between RetCam Ⅲ and binocular indirect ophthalmoscope was analyzed by Kappa test. The detectable rates of tumor between binocular indirect ophthalmoscope, RetCam Ⅲand B scan ultrasound were comparatively analyzed. ResultsBy binocular indirect ophthalmoscope, there were 18 eyes (14.4%) in stage A, 15 eyes (12.0%) in stage B, 10 eyes (8.0%) in stage C, 28 eyes (22.4%) in stage D, and 54 eyes (43.2%) in stage E. Using RetCam Ⅲ, the classification was 18 eyes (14.4%) in stage A, 16 eyes (12.8%) in stage B, 11 eyes (8.8%) in stage C, 27 eyes (21.6%) in stage D, and 53 eyes (42.4%) in stage E. The RB classification of RetCam Ⅲ was quite consistent with binocular indirect ophthalmoscope (Weighted Kappa Coefficient=0.979 8, 95% confidence interval=0.960 1-0.999 5). A total of 150 tumors from stage A-D were observed by binocular indirect ophthalmoscope. In which, 147 tumors (98.0%) were found by RetCam Ⅲ, 122 tumors (81.3%) were found by B scan ultrasound. No serious complication was found in these patients. ConclusionsRetCam Ⅲ can detect RB of different stage in clinic. It is quite consistent with binocular indirect ophthalmoscope.