RESUMEN
We present data on fragile X expression in lymphocytes obtained from the following patients: a university student, an infertile couple, 6 of 22 prostatic cancer patients, a meningioma patient, and members of families with meningioma and familial gliomas. All patients were of normal intelligence. In addition, we report 3 cases of central nervous system (CNS) tumors in more typical fragile X families. We suggest that the fragile X expression as well as the clinical findings may be caused by a viral (or similar) infection. The virus may require a receptor protein coded by one allele of a gene on the X chromosome.
Asunto(s)
Síndrome del Cromosoma X Frágil/etiología , Modelos Biológicos , Neoplasias/etiología , Aberraciones Cromosómicas Sexuales/etiología , Enfermedades por Virus Lento/genética , Fragilidad Cromosómica , Femenino , Síndrome del Cromosoma X Frágil/genética , Síndrome del Cromosoma X Frágil/microbiología , Humanos , Inteligencia , Masculino , Neoplasias/genética , Neoplasias/microbiología , Linaje , Enfermedades por Virus Lento/complicaciones , Cromosoma XRESUMEN
Inducibility or enhancement of fragility at 16q22 by alpha-interferon has been found in a Danish laboratory and in our laboratory. Several other studies were not able to confirm these findings. We present the results of a large study on peripheral blood lymphocytes of 15 selected controls and 146 selected patients treated in vitro by alpha-interferon. In some of our patients parallel studies with distamycin A were performed. Both interferon and distamycin A induced the same fragility, but only in some patients. Both agents were not consistently able to enhance a spontaneously expressed 16q22 fragility. 16q22 is the location of the metallothionein genes, whose transcription is induced by interferon. The induction of the metallothionein gene transcription and the 16q22 fragility, however, do not seem to be directly related. To explain our findings we advance the hypothesis that fragility at 16q22 may be a modification induced by virus(es) with selective tropism for cells which are differently influenced by a pleiotropic action of interferon.
Asunto(s)
Fragilidad Cromosómica , Cromosomas Humanos Par 16 , Interferón Tipo I/farmacología , Distamicinas/farmacología , Humanos , Interferón Tipo I/uso terapéutico , Cariotipificación , Virosis/terapiaRESUMEN
A family with a "fragile site" at 16q22, inducible by both interferon and Distamycin A, is reported. Immunological problems were found in the family. In a sibship of ten, eight children had died in infancy. Our study led to the conclusions that interferon and Distamycin A induce fragility at the same site, which has the same characteristics as the spontaneous fragile site; that a viral hypothesis for this fragility may be supported; and that immunoincompetence of one kind or another must be considered in families presenting a fragile site at 16q22.
Asunto(s)
Fragilidad Cromosómica , Cromosomas Humanos 16-18/ultraestructura , Distamicinas/farmacología , Interferón Tipo I/farmacología , Pirroles/farmacología , Adulto , Sitios Frágiles del Cromosoma , Femenino , Humanos , Cariotipificación , Masculino , MetafaseRESUMEN
The significance of the fragile site on 16 (q21q22) has not yet been fully evaluated. New data will contribute to the understanding of this cytogenetic finding. Therefore we report on four families where a chromosome 16 with fragile site was segregating and such problems as infertility, abortions, malformations, and aneuploidy were present. The hypothesis that this fragile site is a site of viral modification (or integration?) is considered.
Asunto(s)
Cromosomas Humanos 6-12 y X , Aborto Habitual/genética , Adulto , Anencefalia/genética , Aneuploidia , Aberraciones Cromosómicas , Mapeo Cromosómico , Femenino , Variación Genética , Humanos , Recién Nacido , Infertilidad Masculina/genética , Masculino , Embarazo , Virosis/complicacionesRESUMEN
The negative influence of some insecticides on male fertility has been noted. We report our cytogenetic observations on a group of infertile insecticide workers. Increased chromosomal breakage was a constant finding and the Y chromosome was especially damaged. This may account for impaired spermatogenesis. Furthermore, the involvement of heterochromatic chromosomal variants both in the individual susceptibility to the chemically induced damage and in the reproductive fitness is emphasized.
Asunto(s)
Aberraciones Cromosómicas/inducido químicamente , Infertilidad Masculina/inducido químicamente , Insecticidas/envenenamiento , Aberraciones Cromosómicas Sexuales/inducido químicamente , Antiespermatogénicos , Trastornos de los Cromosomas , Cromosomas Humanos 13-15 , Cromosomas Humanos 16-18 , Cromosomas Humanos 4-5 , Heterocromatina , Humanos , Hidrocarburos Clorados , Cariotipificación , Masculino , Compuestos Organofosforados , Testosterona/análisis , Cromosoma YRESUMEN
The chromosomal analysis of a phenotypically normal, moderately oligospermic man is reported. He presented a triple mosaic complement with two autosomally unbalanced cell lines. The cytogenetic results are discussed, and the importance of such investigations in men attending infertility clinics emphasized.
