Abstract
Abstract: :
Purpose: Deleted in polyposis 1–like 1 (Dp1l1) is a recently identified gene that is expressed abundantly in the mouse ganglion cell layer (ARVO2003;2264). The gene consists of 5 exons and encodes 201 amino acid protein. The Dp1l1 gene was mapped to mouse chromosome 10, and the human homologue is located on chromosome 19. Linkage analysis using sibpairs suggested that the region on chromosome 19 shows high lod scores. The purpose of this study was to evaluate human Dp1l1 (hDp1l1) as a candidate gene for primary open–angle glaucoma (POAG) and normal tension glaucoma (NTG). Methods: Eighty–five unrelated Japanese patients with POAG, 65 unrelated patients with NTG, and 80 normal subjects were studied. An informed consent was obtained from all patients. Genomic DNA was extracted from leukocytes of the peripheral blood, and 5 the exons of the hDp1l1 gene were amplified by polymerase chain reaction (PCR) and directly sequenced. Results: We identified a new C to A polymorphism (GCC>GAC) in exon 4 that causes an Ala150Asp amino acid substitution. The frequency of the hDp1l1 CC, CA, and AA genotypes were 66/18/1 in POAG, 52/13/0 in NTG, and 69/11/0 in normal subjects (22.4% vs. 13.8%, 20.0% vs. 13.8%; P = 0.16 and P = 0.37, respectively, for the dominant effect of the hDp1l1 A allele). There was no statistically significant increase in the prevalence of POAG/NTG associated with this base change. Conclusions: Our findings indicate that there is no association with this sequence variant and POAG/NTG. However, our findings do not completely exclude the possibility of an association of POAG/NTG prevalence and hDp1l1 mutation in the Japanese population. We are currently investigating DNA from additional glaucoma subjects and normal control subjects.
Keywords: genetics • gene screening • ganglion cells