Abstract
Abstract: :
Purpose:We have previously completed an initial genome screen to identify the chromosomal locations of POAG susceptibility genes. Follow-up studies performed on 206 sibling pairs continue to support POAG loci on chromosomes 2, 4, 14, 15, 17 and 19, with highest multipoint lod scores for the regions on chromosomes 14 and 15. The purpose of this study is to identify and analyze POAG candidate genes located in the chromosome 14 region. Methods:For this study POAG was defined as age of diagnosis greater than 35, intraocular pressure greater than 22 mm Hg in both eyes, glaucomatous optic nerve damage in both eyes, and visual field loss in at least one eye. Candidate genes located in the chromosome 14 region were identified from public databases (http://genome.ucsc.edu; http://ncbi.nlm.nih.gov). Expression in the eye was determined using the UNIGENE database as well as the NEIBANK. Candidate gene sequences and intron/exon boundaries were obtained from GENBANK and by BLAT and BLAST comparisons of the genome sequence. Translated exons for each gene were amplified using flanking oligonucleotides and the amplification products were sequenced using BIGDYE chemistries and an ABI 310 automated sequencer. Results:Coding exons and intron/exon boundaries for the defender against cell death 1 (DAD1), solute carrier 7A8 (SLC7A8) and bcl2 like 2 (BCL2L2) genes located within the candidate region on chromosome 14 were sequenced in at least 8 families with POAG. Synonymous SNPs were identified in affected individuals in all three genes. A nonsynonymous change was found in the BCL2L2 gene. Conclusion:Sequence variations in the coding regions of three genes located in the region on chromosome 14 associated with POAG have been identified. Most of these changes are synonymous SNPs, although one nonsynonymous change was found. Haplotype analysis and association studies to further evaluate these DNA sequence changes are currently underway.
Keywords: 335 candidate gene analysis • 420 genetics