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| ORIGINAL ARTICLE |
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| Year : 2011 | Volume
: 57
| Issue : 3 | Page : 201-205 |
Polymorphisms of the gamma crystallin A and B genes among Indian patients with pediatric cataract
S Mehra1, S Kapur1, AR Vasavada2
1 Department of Biological Sciences, Birla Institute of Technology and Science- Pilani, Hyderabad Campus, Hyderabad, Andhra Pradesh, India
2 Iladevi Cataract and IOL Research Centre, Memnagar, Ahmedabad, Gujarat, India
Correspondence Address:
S Kapur
Department of Biological Sciences, Birla Institute of Technology and Science- Pilani, Hyderabad Campus, Hyderabad, Andhra Pradesh
India
 Source of Support: Grants from Indian Council of Medical Research, New
Delhi, India to Dr. Suman Kapur and ICMR senior research fellowship to
Mrs. Shipra Mehra, Conflict of Interest: There is no conflict of interest
among any of the authors of the paper being submitted  | Check |
DOI: 10.4103/0022-3859.85205
Background : Previous familial studies have reported co-segregation of mutation in gamma crystallin A and B CRYGA and CRYGB genes with childhood cataract. Aim : We investigated association of nucleotide variations in these genes in subjects with and without pediatric cataract from India. Settings and Design : The study included 195 pediatric subjects including healthy children with no ocular defects and pediatric cataract cases. Materials and Methods : Subjects were genotyped by PCR-RFLP method for exonic and intronic genetic variations in CRYGA and CRYGB. Statistical Analysis : The association of these polymorphisms with cataract was estimated by two way contingency tables and the risk allele was also analyzed for their functional impact using in silico tools. Results : No significant difference was observed between cases and control subjects for the frequencies of SNPs G198A (Intron A), T196C (Exon 3) of CRYGA and G449T (Exon 2) of CRYGB gene. -47C allele of rs2289917 in CRYGB showed the strongest association with cataract (Odd Ratio-OR=3.34, 95% Confidence Interval-CI 95% =1.82-6.12, P=0.00007). In silico analyses revealed that this polymorphism lies in a phylogenetically conserved region and impacts binding of a transcription factor, viz. progesterone receptor (PR) to CRYGB promoter. Conclusion : rs2289917 risk allele showed a strong association with increased vulnerability for pediatric cataract. The findings suggest that this association may be a secondary phenomenon related to genetic variation playing critical role in lens development during perinatal and/or pediatric growth. Present exploratory study provides a basis for further defining the role of PR as a regulator of CRYG locus in lens formation/transparency.
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