RESUMEN
Whereas a recent study reported an increased risk of colorectal cancer associated with any HFE germ line mutation (C282Y or H63D), other investigators have concluded there is no increased risk, or that any increase is dependent on polymorphisms in HFE-interacting genes such as the transferrin receptor (TFR). We have established the frequency of HFE mutations in colorectal cancer patients (n = 327) with a family history of the disease and randomly selected controls (n = 322); this design increases greatly the study's power. Genotyping for the TRF S142G polymorphism was also conducted on a large proportion of the study group. Using PCR, restriction enzyme mapping, sequencing followed by data analysis with Fisher's exact test and logistic regression, we show that the presence of any HFE mutation (Y282 or D63) was not associated with colorectal cancer risk (P = 0.57). In contrast, individuals compound heterozygous for both mutations (15 cases versus 5 controls) had thrice the odds of developing colorectal cancer (odds ratio, 3.03; 95% confidence interval, 1.06-8.61) compared with those with a single mutation. This finding did not quite reach statistical significance after allowing for multiple post hoc testing (P(observed) = 0.038 versus P = 0.025, with Bonferonni correction). Overall, our data indicate that individuals with a single HFE mutation, C282Y or H63D, are unlikely predisposed to develop colorectal cancer. However, risk of colorectal cancer might be increased by compound heterozygosity for the HFE mutations in the small number of subjects studied. TFR gene polymorphism was not an independent risk factor and did not modify the disease risk associated with HFE mutation.
Asunto(s)
Neoplasias Colorrectales/etiología , Neoplasias Colorrectales/genética , Mutación de Línea Germinal , Antígenos de Histocompatibilidad Clase I/genética , Proteínas de la Membrana/genética , Polimorfismo Genético , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Genotipo , Proteína de la Hemocromatosis , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Reacción en Cadena de la Polimerasa , Factores de RiesgoRESUMEN
OBJECTIVES: To compare relative attachment level data (RAL) selected by the Option-4 algorithm (O-4), Modified Option-4 algorithm (MO-4), Option-3 method (O-3) and Double Pass method (DP) from a common dataset and to determine the most efficient method in eliminating outliers. MATERIAL AND METHODS: A single clinician recorded full mouth RAL with the Florida Disc Probe on four occasions over 6 months in 16 subjects (mean age 48.1 years) with untreated moderate Chronic Adult Periodontitis (mean Probeable Crevice Depth 2.9 mm). RESULTS: 2312 sites were available for analysis. Within-visit correlation coefficients for the two selected RAL measurements were 0.98 (P < 0.001) for O-4, MO-4 and O-3 and >or= 0.92 (P < 0.001) for DP. The maximum mean differences of within-visit RAL were - 0.05 mm for O-4, - 0.03 mm for MO-4, - 0.03 mm for O-3 and - 0.02 mm for DP. The standard deviations of these differences were Asunto(s)
Pérdida de la Inserción Periodontal/diagnóstico
, Periodoncia/instrumentación
, Adulto
, Algoritmos
, Análisis de Varianza
, Distribución de Chi-Cuadrado
, Instrumentos Dentales
, Diagnóstico Bucal/instrumentación
, Diagnóstico Bucal/métodos
, Femenino
, Humanos
, Masculino
, Persona de Mediana Edad
, Periodontitis/patología
, Reproducibilidad de los Resultados
, Sensibilidad y Especificidad
, Estadísticas no Paramétricas