1/8. Triploid pregnancy after ICSI of frozen testicular spermatozoa into cryopreserved human oocytes: case report.Although freezing oocytes is ethically more acceptable than cryopreservation of embryos, variable oocyte survival, fertilization rate and possible risk of increased ploidy after cryopreservation have precluded the widespread clinical application of oocyte cryopreservation in assisted reproduction techniques. We report a triploid pregnancy from intracytoplasmic sperm injection of recombinant FSH-stimulated frozen/thawed testicular spermatozoa into cryopreserved oocytes in a hormone replacement cycle. To our knowledge, this is the first report of a pregnancy where both gametes have been frozen. It illustrates the need for further research when applying new techniques in assisted reproduction.- - - - - - - - - - ranking = 1keywords = fertilization (Clic here for more details about this article) |
2/8. 47,XX mar karyotype containing genes from the azoospermia factor region. A case report.BACKGROUND: Abnormal embryo development is the major cause of implantation failure and accounts for the low rate of human fertility in vitro and in vivo. Chromosome abnormalities are widely involved in this process through meiotic nondisjunction, fertilization abnormalities and mitotic nondisjunction. CASE: In our assisted reproductive technology program a couple underwent cytogenetic analysis. The woman had a 47,XX mar karyotype. We investigated this patient by chromosome analysis, fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) dna analysis. The marker chromosome was found to be very similar to a y chromosome in size and QFQ staining pattern. Therefore, it was tested by FISH using alpha- and beta-satellite dna specific for the y chromosome, some YACs specific for the long arm of the y chromosome and alpha-satellite dna specific for 15 chromosomes as probes. In order to define this marker, the next step was PCR amplification of the whole genomic dna using specific landmarks (sequence-tagged sites) to encompass the azoospermia factor (AZF) region on the long arm of the y chromosome. CONCLUSION: A woman had an extra chromosome containing centromeric dna derived from the Y and 15 other chromosomes, heterochromatic regions derived from 15 chromosomes and a large heterochromatic block at the end of the long arm that definitely was not y chromosome heterochromatin (beta-satellite). PCR showed several genes of the y chromosome long arm that are assumed to be involved in male gametogenesis. Phenotypic effects could not be excluded because of the presence of AZF genes. Oocyte karyotyping might better explain the role of the genetic problem on female infertility.- - - - - - - - - - ranking = 1keywords = fertilization (Clic here for more details about this article) |
3/8. Sperm chromosomal abnormalities are linked to sperm morphologic deformities.OBJECTIVE: To describe the association between specific sperm morphologic abnormalities and sperm chromosomal abnormalities on multicolor interphase fluorescence in situ hybridization (FISH). DESIGN: Case report.reproductive medicine unit in a tertiary referral center. PATIENT(S): Three infertile men with severe oligoasthenospermia and total teratozoospermia who were referred for IVF treatment. MAIN OUTCOME MEASURE(S): incidence of spermatozoal chromosomal aneuploidy for chromosome 18 and the sex chromosomes by using FISH. RESULT(S): Morphologic assessment of sperm revealed a high incidence of double heads, multinucleated sperm heads, and multiple tails. Hormone profiles and karyotyping of peripheral lymphocytes were normal in the three men. The proportion of sperm with disomy, trisomy and tetrasomy for chromosome 18, and the sex chromosomes in each patient was 100%, 76%, and 82.5%, respectively. CONCLUSION(S): Specific morphologic abnormalities of sperm may be associated with higher incidence of chromosomal abnormalities. Resolving infertility by offering patients in vitro fertilization/intracytoplasmic sperm injection must be approached with caution because of the significant risk for embryonic aneuploidy and chromosomal abnormalities in any subsequent offspring.- - - - - - - - - - ranking = 1keywords = fertilization (Clic here for more details about this article) |
4/8. Testicular regression syndrome.Recently, the testicular regression syndrome has been reported as being representative of a clinical range of XY agonadal persons. A patient with aberrant fetal sexual development is described. Of particular interest is that all of the tissues examined--the rudimentary uterine horn and the 2 fallopian tubes--displayed an XY chromosome complement. Correlation was made between the known temporal events of embryogenesis of the testes and the apparent time of regression of the testes. In this patient, the insult to testicular development, with subsequent testicular regression, occurred between 48 and 60 days after fertilization. This review supports the previously reported thesis that in certain XY persons the testes are irreparably damaged at a critical stage in fetal development, and that this critical stage is represented by a range of abnormalities of genital development. Possible causes and simplified nomenclature for such gonadal damage are presented.- - - - - - - - - - ranking = 1keywords = fertilization (Clic here for more details about this article) |
5/8. Origin of chi46,XX/46,XY chimerism in a human true hermaphrodite.Using chromosome heteromorphisms and blood cell types as genetic markers, we demonstrated chimerism in a chi46,XX/46,XY true hermaphrodite. The pattern of inheritance of the chromosome heteromorphisms indicates that this individual was probably conceived by the fertilization, by two different spermatozoa, of an ovum and the second meiotic division polar body derived from the ovum and subsequent fusion of the two zygotes. This conclusion is based on the identification of the same maternal chromosomes 13, 16, and 21 in both the 46,XX and 46,XY cells of the patient. In the two cell lines of the chimera, chromosomal markers showed different paternal No. 9 chromosomes and sex chromosomes, as well as the same paternal chromosome 22.- - - - - - - - - - ranking = 1keywords = fertilization (Clic here for more details about this article) |
6/8. triploidy caused by endoreduplication in a human zygote obtained after in-vitro fertilization.cytogenetic analysis of a presumably tripronuclear zygote revealed that triploidy was caused by an endoreduplicated 46,XX complement. The remaining chromosomes yielded a hyperhaploid karyotype of 28,Y, 2, 3C, D. The origin of this chromosomal composition is obscure. Besides endoreduplication in a normal 23,X oocyte pronucleus and fertilization by a normal 23,Y spermatozoon, an additional female pronucleus might have been formed due to an irregular chromosome distribution during second meiotic division. On the other hand, penetration by a hyperhaploid spermatozoon cannot be excluded with certainty.- - - - - - - - - - ranking = 5keywords = fertilization (Clic here for more details about this article) |
7/8. Case report: high fertilization rate in conventional in-vitro fertilization utilizing spermatozoa from an oligozoospermic subject presenting microdeletions of the y chromosome long arm.A case is reported in which a high fertilization rate was achieved by conventional in-vitro fertilization (IVF), using spermatozoa from an oligozoospermic man carrying a microdeletion of the long arm of the y chromosome. The patient presented with idiopathic infertility of 10 years duration; the fertility status of his wife was completely normal. After IVF, five out of eight oocytes retrieved showed normal fertilization and four showed normal embryo cleavage. Four embryos were transferred; however, pregnancy did not result. These results demonstrate that spermatozoa from oligozoospermic patients carrying a Yq microdeletion are fully competent in achieving capacitation, acrosome reaction and fertilizing ability during IVF. Therefore, although definitive conclusions cannot be made from a single case report, we suggest that Yq microdeletion analysis should be considered in oligozoospermic patients undergoing conventional IVF.- - - - - - - - - - ranking = 11keywords = fertilization (Clic here for more details about this article) |
8/8. True hermaphroditism with XX/XY sex chromosome mosaicism: report of a case.A case of true hermaphroditism with 46, XX/46, XY karyotype is reported. The propositus, reared as a male, showed ambiguous external genitalia with perineoscrotal hypospadias, and internal genitalia represented by bilateral ovotestes, normal uterus and tubes. Periodic menstrual bleedings appeared at puberty. The endocrinologic data demonstrated the secretory activity of both the ovarian and the testicular tissue. The analysis of red cell, lymphocyte and serum markers, done on the propositus and on his parents, failed to show any evidence of double fertilization. On this basis, the origin of the XX/XY condition (mosaicism versus chimerism) and its developmental consequences are discussed.- - - - - - - - - - ranking = 1keywords = fertilization (Clic here for more details about this article) |