BACKGROUNDPrimary open-angle glaucoma (POAG) is characterized by optic nerve damage and consists of a group of genetically heterogeneous disorders. This study was to investigate the associations of genetic and environmental factors with POAG in a hospital-based Chinese population.

METHODSThirty-two adult onset POAG patients and 96 age-sex matched control subjects were studied by multivariable logistic regression analysis for the relationships between POAG and its risk factors including family history, diabetes, hypertension, cardiovascular diseases, cigarette smoking, alcohol consumption and polymorphisms of the myocilin and the optineurin genes.

RESULTSUnivariate analysis showed that POAG was related to family history, cardiovascular disease, alcohol consumption and a myocilin sequence alteration (T353I) (P < 0.04). Multivariable logistic regression analysis confirmed that POAG was significantly associated with family history (OR = 20.2), hypertension (OR = 3.58), cigarette smoking (OR = 10.8), alcohol consumption (OR = 0.028) and T353I (OR = 6.03, all P < 0.05).

CONCLUSIONSFamily history, hypertension, cigarette smoking and T353I in the myocilin gene are risk factors for POAG. Alcohol consumption, however, has a protective effect.

Adult ; Aged ; Aged, 80 and over ; Alcohol Drinking ; adverse effects ; Cytoskeletal Proteins ; Eye Proteins ; genetics ; Female ; Glaucoma, Open-Angle ; etiology ; genetics ; Glycoproteins ; genetics ; Humans ; Hypertension ; complications ; Logistic Models ; Male ; Middle Aged ; Risk Factors ; Smoking ; adverse effects

OBJECTIVETo detect single nucleotide polymorphisms (SNPs) of the myocilin (MYOC) gene and to investigate their associations with primary open-angle glaucoma (POAG).

METHODSOne hundred and fifty-seven sporadic patients with POAG and 155 unrelated control subjects without POAG were recruited from staff and visitors to the Prince of Wales Hospital between 1998 and 2000. All study subjects are ethnic Chinese living in Hong Kong. The two populations were matched in frequencies of gender and age. The SNPs of the MYOC gene in POAG patients and control subjects were screened and identified by high throughout conformation sensitive gel electrophoresis and fluorescent labeling automated sequencing. The genotype frequencies of each SNP in the two groups were compared by the Chi2 test or Fisher's exact 2-tailed test.

RESULTSA total of seventeen SNPs were identified from 2172 bp long of the MYOC gene, including all 3 exons and adjacent non-coding regions. The identified SNPs were 1-83G --> A, G12R, P16L, A17S, R46X, R76K, R91X, T123T, D208E, L215P, 730+35A --> G, A260A, I288I, E300K, T353I, Y471C and 1515+73G --> C, respectively. Of these, R91X, E300K and Y471C were found only in POAG patients. A significant difference between POAG patients and control subjects was found in the genotype frequencies of 1515+73G --> C. The frequency of the heterozygote (CG) was 0.6% in POAG patients, significantly less than the 4.5% in control subjects (Fisher's exact 2-tailed test, P=0.036, OR=0.136, 95%CI=0.022-0.828). No significant difference was found between the two populations in genotype frequencies of all other SNPs.

CONCLUSIONThe polymorphisms of the MYOC gene may be related to POAG.

Adult ; Aged ; Aged, 80 and over ; Amino Acid Substitution ; Base Sequence ; Case-Control Studies ; Cytoskeletal Proteins ; DNA ; chemistry ; genetics ; DNA Mutational Analysis ; Eye Proteins ; genetics ; Female ; Gene Frequency ; Genotype ; Glaucoma, Open-Angle ; genetics ; pathology ; Glycoproteins ; genetics ; Humans ; Male ; Middle Aged ; Point Mutation ; Polymorphism, Single Nucleotide

BACKGROUND/AIMS: We determined the rates of metachronous colorectal neoplasm in colorectal cancer (CRC) patients after resection for right (R)-sided or left (L)-sided cancer. METHODS: Consecutive CRC patients who had undergone surgical resection for curative intent in our hospital between 2001 and 2004 were identified. R-sided colonic cancers refer to cancer proximal to splenic flexure whereas L-sided cancers include rectal cancers. Patients were included only if they had a clearing colonoscopy performed either before or within 6 months after the operation. Findings of surveillance colonoscopy performed up to 5 years after colonic resection were included in the analysis. RESULTS: Eight hundred and sixty-three CRC patients underwent curative surgical resection during the study period. Three hundred and twenty-seven patients (107 R-sided and 220 L-sided) fulfilled the inclusion criteria and had at least 1 postoperative surveillance colonoscopy performed. The proportion of patients who had polyp and adenoma on surveillance colonoscopy was significantly higher among patients with L-sided than R-sided cancers (polyps: 30.9% vs. 19.6%, P=0.03; adenomas: 25.5% vs. 13.1%, P=0.01). The mean number of adenoma per patient on surveillance colonoscopy was also higher for patients with L-sided than R-sided tumors (0.52; 95% confidence interval [CI], 0.37–0.68 vs. 0.22; 95% CI, 0.08–0.35; P < 0.01). Multivariate analysis showed that L-sided cancers, age, male gender and longer follow-up were independent predictors of adenoma detection on surveillance colonoscopy. CONCLUSIONS: Patients with Lsided cancer had a higher rate of metachronous polyps and adenoma than those with R-sided cancer on surveillance colonoscopy.
Adenoma* ; Colon* ; Colon, Transverse ; Colonic Neoplasms* ; Colonoscopy ; Colorectal Neoplasms ; Follow-Up Studies ; Humans ; Male ; Multivariate Analysis ; Polyps ; Rectal Neoplasms ; Recurrence