Síndrome frágil X: correlación clínica, citogenética y molecular en una familia

Estudios recientes han permitido caracterizar molecularmente el defecto genético o mutación FMR-1 del síndrome frágil X. Esta mutación consiste en variaciones de repeticiones del triplete CGG del gen, que varían del rango normal a la mutación completa y pasan por rangos intermedios o premutaciones. Debido a que el individuo afectado además expresa un porcentaje variable de sitio frágil Xq27.3 (FRAXA) en su cariotipo, en este trabajo se presenta una correlación clínica y citogenética con la caracterización molecular del gen FMR-1 realizada por 2 métodos directos: Southern blot y reacción en cadena de la polimerasa (PCR) en 5 varones afectados y 5 mujeres portadoras, a propósito del diagnóstico prenatal en una de ellas. El análisis de las caracterizaciones clínicas, físicas y neuropsicológicas previamente delineadas, llevaron a la conclusión de que éstas, así como la frecuencia en porcentaje de FRAXA, se correlacionan en los varones afectados con la elongación que experimenta la mutación al trasmitirse de una generación a la siguiente a través de mujeres portadoras, en quienes por otra parte, estas características son heterogéneas y susceptibles a sobrelapamiento tanto por efecto genómico como por factores ambientales psicofamiliares.

Recent studies have allowed to characterize molecularly the genetic defect or FMR-1 mutation of the fragile X syndrome. This mutation consists in variations of repetitions of the gene's CGG triplet that came from the normal range to the complete mutation, passing through intermediate ranges or premutations. Due to the fact that the affected individual also shows a variable percentage of Xq27.3 fragile site (FRAXA) in his karyotype, it is presented in this paper a clinical and cytogenetic correlation with the molecular characterization of the FMR-1 gen carried out by 2 direct methods: Southern Blot and polymerase chain reaction (PCR) in 5 affected males and 5 female carriers, one of them with prenatal diagnosis. The analysis of the clinical, physical and neuropsychological characterizations previously delineated, led to the conclusion that these, as well as the FRAXA frequency in percentage, are correlated among the affected males with the elongation the mutation suffers on being transmitted from one generation to another through female carriers, in whom these characteristics are heterogeneous and susceptible to overlapping as a result of genomic effect and of environmental psychofamilial factors.

Detection and analysis of biochemically symbolized genes in closed colony Kunming mice / 第三军医大学学报

Twenty-one biochemically symbolized genetic sites on 11 chro mosomes of closed colony Kunming mice were located with electrophoresis.The genetic picture of the mouse was established and it was confirmed that the mouse showed definite features of genetic polymorphism and hereditary stability.

Frequencies distribution of 5-HT2A T102C genotypes in the schizophrenia patients / 解放军医学杂志

Objective To investigate the geographic distribution of 5-HT2A T102C genotypes frequency in the PLA schizophrenia patients. Methods The 5-HT2A receptor gene T102C polymorphism was analyzed for genotyping by the method of polymerase chain reaction(PCR)in 177 male PLA schizophrenia patients. Results The distribution of 5-HT2A genotypic frequencies in 177 male PLA schizophrenia patients were 0.07~0.33(? 2=4.44,P=0.617 1) for A1A1, 0.50~0.72 for A1A2 (? 2=1.14, P=0.942 2), and 0.17~0.29 for A2A2 (? 2=0.93, P=0.985 7), respectively. There was no significant correlation between 5-HT2A frequencies and different populations. Conclusion The frequencies of 5-HT2A T102C genotypes in the PLA schizophrenia patients were uniform in different populations.