RESUMEN
Identification of clonal IGH, IGK and IGL gene rearrangements offers diagnostic adjunct in suspected B-cell neoplasms. However, many centres omit IGL analysis as its value is uncertain. A review of 567 cases with IGH, IGK and IGL rearrangement assessed using BIOMED-2 assays showed clonal immunoglobulin gene rearrangement in 54% of cases, of which 24% had a clonal IGL rearrangement. In two cases, the clonal rearrangement was detected exclusively by IGL analysis. This finding demonstrates the added value of IGL analysis for clonality assessment, especially in suspected B-cell neoplasms in which a clonal IGH and/or IGK rearrangement is not detected or is equivocal.
Asunto(s)
Reordenamiento Génico de Cadena Ligera de Linfocito B , Genes de las Cadenas Ligeras de las Inmunoglobulinas/genética , Cadenas lambda de Inmunoglobulina/genética , Linfoma de Células B/diagnóstico , Linfoma de Células B/genética , Anciano , Femenino , Genes Relacionados con las Neoplasias , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas kappa de Inmunoglobulina/genética , Linfoma de Células B/patología , Clasificación del Tumor , Células Madre Neoplásicas/patología , Reacción en Cadena de la Polimerasa/métodosRESUMEN
BACKGROUND: Age-related macular degeneration is the most common cause of blindness in Western populations. Susceptibility is influenced by age and by genetic and environmental factors. Complement activation is implicated in the pathogenesis. METHODS: We tested for an association between age-related macular degeneration and 13 single-nucleotide polymorphisms (SNPs) spanning the complement genes C3 and C5 in case subjects and control subjects from the southeastern region of England. All subjects were examined by an ophthalmologist and had independent grading of fundus photographs to confirm their disease status. To test for replication of the most significant findings, we genotyped a set of Scottish cases and controls. RESULTS: The common functional polymorphism rs2230199 (Arg80Gly) in the C3 gene, corresponding to the electrophoretic variants C3S (slow) and C3F (fast), was strongly associated with age-related macular degeneration in both the English group (603 cases and 350 controls, P=5.9x10(-5)) and the Scottish group (244 cases and 351 controls, P=5.0x10(-5)). The odds ratio for age-related macular degeneration in C3 S/F heterozygotes as compared with S/S homozygotes was 1.7 (95% confidence interval [CI], 1.3 to 2.1); for F/F homozygotes, the odds ratio was 2.6 (95% CI, 1.6 to 4.1). The estimated population attributable risk for C3F was 22%. CONCLUSIONS: Complement C3 is important in the pathogenesis of age-related macular degeneration. This finding further underscores the influence of the complement pathway in the pathogenesis of this disease.
Asunto(s)
Complemento C3/genética , Degeneración Macular/genética , Polimorfismo de Nucleótido Simple , Anciano , Estudios de Casos y Controles , Complemento C3/química , Complemento C5/genética , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Modelos Logísticos , Masculino , Oportunidad Relativa , Estructura Cuaternaria de ProteínaRESUMEN
BACKGROUND: Family history is considered a risk factor for age-related macular degeneration (AMD). With the advent of effective therapy for the disease, the importance of family history merits further investigation. This study quantifies the risk associated with family history, first, by a case-control study of reported family history and, second, by examining the siblings of AMD cases. METHODS: The authors recruited cases with advanced AMD, spouses and siblings. All subjects were carefully phenotyped. Clinical findings in the siblings were compared with spouses. Information about family history was collected. The ORs for reported family history of AMD were calculated. Analyses were adjusted for age, smoking and genotype. RESULTS: 495 AMD cases, 259 spouses and 171 siblings were recruited. The OR for AMD was 27.8 (CI 3.8 to 203.0; p=0.001) with a reported family history of an affected parent and 12.0 (CI 3.7 to 38.6; p<0.0001) with a history of an affected sibling. ORs adjusted for age and smoking were higher. Examination of siblings confirmed their increased risk with 23% affected by AMD and an OR of 10.8 (4.5 to 25.8; p<0.0001). Adjusting for age increased the OR to 16.1 (6.2 to 41.8). CONCLUSION: The risk of AMD is greatly increased by having an affected first-degree relative. Those at risk need to be made aware of this and AMD patients should advise siblings and children to seek prompt ophthalmological advice if they develop visual symptoms of distortion or reduced vision.
Asunto(s)
Degeneración Macular/epidemiología , Relaciones entre Hermanos , Trastornos de la Visión/epidemiología , Anciano , Estudios de Casos y Controles , Complemento C3/genética , Factor B del Complemento/genética , Factor H de Complemento/genética , Salud de la Familia , Femenino , Genotipo , Humanos , Degeneración Macular/genética , Masculino , Oportunidad Relativa , Polimorfismo de Nucleótido Simple , Prevalencia , Proteínas/genética , Factores de Riesgo , Encuestas y Cuestionarios , Trastornos de la Visión/genéticaRESUMEN
OBJECTIVES: Age-related macular degeneration (AMD) is the commonest cause of blindness in Western populations. Risk is influenced by age, genetic and environmental factors. Complement activation appears to be important in the pathogenesis and associations have been found between AMD and genetic variations in complement regulators such as complement factor H. We therefore investigated other complement regulators for association with AMD. METHODS: We carried out a case-control study to test for association between AMD and single nucleotide polymorphisms (SNPs) spanning the genes encoding complement factor P (CFP, properdin), CD46 (membrane cofactor protein, MCP), CD55 (decay accelerating factor, DAF) and CD59 (protectin). All cases and controls were examined by an ophthalmologist and had independent grading of fundus photographs to confirm their disease status. RESULTS: 20 SNPs were genotyped in 446 cases and 262 controls. For two SNPs with p-values approaching significance additional subjects were genotyped to increase the numbers to 622 cases and 359 controls. There was no evidence of association between AMD and any of the SNPs typed in CFP, CD46, CD55 or CD59. CONCLUSIONS: In a case-control sample that has shown the well established associations between AMD and variants in CFH, CFB and C3 there was absence of association with SNPs in CFP, CD46, CD55 and CD59. This suggests that these are not important susceptibility genes for AMD.