Chromosome abnormalities are the most commonly cause of sterility, infertility and mortality in human reproductive process. Most of the molecular and cytogenetic studies on these aberrations have been carried out in somatic cells from livebirth and spontaneous abortion surveys. However, only and indirect information about the etiology and risk in the offspring have been obtained from somatic studies because the mechanisms that origin the chromosome abnormalities take out during the production of gametes. Turner syndrome (45,X) (79%) (Hassold et al, 1992), Klinefelter syndrome y Magenis, 1988) show the highest incidence of paternal origin. In the last years, direct analyses of human sperm chromosomes have been possible thanks to description of a heterologous in vitro fusion of zona-free hamster oocytes and human sperm (Martin et al, 1983). Up to now this is the only method availabel to study the frequency and types of chromosomal abnormalities in human sperm. \i In situ\i0 fluorescence hybridization (FISH), with probes and libraries of DNA (chromosome painting) (Williams et al, 1993; Rosenberg et al., 1992), allow a fast and reliable analysis of numerical and structural chromosomal e abnormalities in nucleic and metaphases of spermatozoa. Using this procedure it would be possible to improve the results obtained by the hamster -human fusion technique. In this project, we propose using cytogenetic and molecular studies in sperm from men with offspring with Turner syndrome, Klinefelter syndrome and \i de novo\i0 structural aberrations, to stablish the real risk in the offspring and to determine the origin and risk factors of these abnormalities.
|Effective start/end date||1/11/96 → 1/11/99|