000 04479nam a22002297a 4500
005 20151207093137.0
008 151207b2015 xxu||||| |||| 00| 0 eng d
041 _aeng
082 _a2370-T
100 _aSaeeda Kalsoom (2007-VA-555)
_918132
110 _cDr. Muhammad Wasim)
_95021
245 _aMutational Screening Of The RB1 Gene In Pakistani Patients With Retinoblastoma
260 _c2015
300 _a178p.;
502 _aRetinoblastoma is a neonatal intraocular tumor caused by biallelic inactivation of RB1 gene. Rb patients and asymptomatic carriers undergo a series of clinical tests for diagnosis and tumor treatment. These clinical examinations prove to be expensive and time consuming. On the other hand if the proband’s RB1 gene mutation status is determined by genetic testing, it can prove as more significant and cost effective diagnostic methods. Secondly, only those asymptomatic or at risk carriers with the mutation, require clinical surveillance while those proven to be unaffected do not require additional clinical examinations. Furthermore early diagnosis of Rb by molecular testing can enable and enhance clinical management, earlier treatment, follow-up care, carrier screening, genetic counseling, prenatal diagnosis and reproductive planning in predisposed families. Irrespective of the importance of molecular testing of Rb patients, in Pakistan only a few clinical reports on Rb are available so, there was a dire need to find RB1 mutations in Pakistani Rb patients and to set a molecular based diagnosis for poor affected families. Keeping in view the importance of molecular diagnosis, in this study a reliable genetic test has been developed to detect the RB1 germline mutations in Pakistani Rb patients. During this study, 70 Rb patients including 38 unilateral and 32 bilateral cases were enrolled, from different regions of Pakistan. By using direct sequencing method, seven novel and twelve reported RBI mutations were found. The novel mutations included three frameshift mutations (c.1116_1119delCACT in exon 11, c.1436_1437delAC in exon 16 and c.2060_2061insTCATT in exon 20) and four substitutions (c.148G>T in exon 2, c.610G>T in exon 2, g.94G>C in exon 7, c.947A>T in exon 10 and g.1991G>C in promoter region) while twelve reported mutations in 146 22 patients included, 9 substitutions (c.160G>T in exon 2, c.289G>T in exon 3, c.751C>T in exon 8, c.920C>T in exon 9, c.967G>T in exon 10, c.1072C>T in exon 11, c.1654C>T in exon 17, c.2063T>C in exon 20 and c.2359C>T in exon 23), one frameshift mutation (c.772_776del in exon 8) and two splice site mutations (c.380+1G>T and c.1215+1G>A in intron 3 and 12 respectively). Mutation detection rate was found to be 77.8% in (7/9) bilateral familial, 50% in (2/4) unilateral familial, 56.5% in (13/23) bilateral sporadic and 14.7% in (5/34) unilateral sporadic patients while overall rate of mutations in bilateral and unilateral patients was detected as 62.5% (20/32) and 18.4% (7/38) respectively. Beside mutations one novel c.940-64C>T (intron 9) and nine reported intronic variants c.380+45 C>T (intron 3), c.501-77G>A (intron 4), c.1128-72T>G (intron 11), c.1695+99A>T (intron 17), c.1695-1696delAA (intron 17), c.1815- 104A>G (intron 18), c.1961-10T>C (intron 19), c.2663+33T>C (intron 25) and c.2664-10T>A (intron 25) were also found. Carrier screening facility was also provided to six asymptomatic siblings (as possible carriers) of familial proband but none of them was found to be diseased. Hopefully, in future the findings and developed protocol of this study will help to reveal the molecular basis of Rb in Pakistani Rb patients which additionally help to secure vision and life of Rb patients. Further, in Pakistan there is dire need to develop “National Rb Registry Centre”, to register all new Rb cases for finding incidence rate and prevalence of Rb in Pakistan. Beside this other related issues like financial constraints, health education, planning and awareness about Rb, occupational training for health providers, capacity building for neonatal ophthalmologic screening and cosmetic rehabilitation for surviving Rb patients are important and should consider.
650 _aDepartment of Molecular Biology and Biotechnology
_911414
650 _aPhd. Theses
_917640
700 _aDr. Khushnooda Ramzan
_918133
700 _aDr. Ali Raza Awan
_95023
700 _aDr. Aftab Ahmad Anjum
_95781
942 _cTH
999 _c6666
_d6665