1/96. Preimplantation genetic diagnosis of a reciprocal translocation t(3;11)(q27.3;q24.3) in siblings.Preimplantation genetic diagnosis (PGD) was performed in two couples to avoid chromosomally unbalanced progeny in a family in which a brother and a sister carry an identical maternally inherited balanced translocation t(3;11)(q27.3;q24.3). Embryos were biopsied 3 days after fertilization and blastomeres were analysed by fluorescent in-situ hybridization (FISH). Embryos were classified as unbalanced or normal/balanced. In the first case, the male carrier and his wife underwent one IVF/PGD treatment cycle. In all, 18 embryos were analysed. Of those, 15 revealed an unbalanced karyotype. For one embryo, results were not conclusive, from one embryo results were contradictory and one embryo was classified as normal/balanced and subsequently transferred. A singleton pregnancy was achieved. The PGD analysis was confirmed at 16 weeks gestation by amniocentesis. At term, a healthy girl with a balanced karyotype was born. Pregnancy and delivery were without complications. In the second case, the female carrier and her husband underwent two IVF/PGD treatment cycles. During the first cycle, three embryos were analysed. One embryo revealed an unbalanced karyotype and two embryos were designated a normal/balanced karyotype and transferred but no pregnancy was achieved. During the second PGD cycle three embryos were analysed. Of those, none appeared suitable for transfer. The couple decided not to undergo further treatment. Our results indicate that for individuals carrying a reciprocal translocation PGD is a feasible approach to obtain embryos with a normal chromosome balance and to avoid both spontaneous and induced abortion.- - - - - - - - - - ranking = 1keywords = abortion (Clic here for more details about this article) |
2/96. Human male infertility: chromosome anomalies, meiotic disorders, abnormal spermatozoa and recurrent abortion.Human male infertility is often related to chromosome abnormalities. In chromosomally normal infertile males, the rates of chromosome 21 and sex chromosome disomy in spermatozoa are increased. Higher incidences of trisomy 21 (seldom of paternal origin) and sex chromosome aneuploidy are also found. XXY and XYY patients produce increased numbers of XY, XX and YY spermatozoa, indicating an increased risk of production of XXY, XYY and XXX individuals. Since XXYs can reproduce using intracytoplasmic sperm injection (ICSI), this could explain the slight increase of sex chromosome anomalies in ICSI series. Carriers of structural reorganizations produce unbalanced spermatozoa, and risk having children with duplications and/or deficiencies. In some cases, this risk is considerably lower or higher than average. These patients also show increased diploidy, and a higher risk of producing diandric triploids. Meiotic disorders are frequent in infertile males, and increase with severe oligoasthenozoospemia (OA) and/or high follicle stimulating hormone (FSH) concentrations. These patients produce spermatozoa with autosomal and sex chromosome disomies, and diploid spermatozoa. Their contribution to recurrent abortion depends on the production of trisomies, monosomies and of triploids. The most frequent sperm chromosome anomaly in infertile males is diploidy, originated by either meiotic mutations or by a compromised testicular environment.- - - - - - - - - - ranking = 5keywords = abortion (Clic here for more details about this article) |
3/96. An inherited translocation t(4;15) (p16;q22) leading to two cases of partial trisomy 15.A four year old girl with severe mental retardation and multiple congenital abnormalities manifested "partial trisomy 15". Her mother, pregnant at the time of examination, possessed a balanced translocation which, after banding techniques, was identified as t(4;15)(p16;q22). Amnio-centesis revealed the karyotype of the fetus to be identical to that of the proposita and a therapeutic abortion was performed. Prenatal investigation of a subsequent pregnancy revealed a normal male karyotype. Comparison of the proposita and aborted fetus of this family with the 5 reported other cases of "partial trisomy 15" does not allow for a precise recognizable clinical syndrome.- - - - - - - - - - ranking = 1keywords = abortion (Clic here for more details about this article) |
4/96. Delineation of a complex karyotypic rearrangement by microdissection and CGH in a family affected with split foot.We report on a male patient and members of his family with additional material in chromosome 3. This derivative chromosome 3 was transmitted from his mother who had a complex rearrangement between chromosomes 2, 3, and 7. It was possible to delineate her chromosomal rearrangement by microdissection and reverse painting and to exclude these aberrations from being responsible for neonatal deaths and several abortions in this family. Two members of this family suffer from ectrodactyly or split hand/foot malformations (SHFM) of the feet which possibly correlates with the derivative chromosome 7 containing a breakpoint in the SHFM1 critical region involving several homeobox genes.- - - - - - - - - - ranking = 1keywords = abortion (Clic here for more details about this article) |
5/96. Outcome of preimplantation genetic diagnosis of translocations.OBJECTIVE: To review 35 cases of preimplantation genetic diagnosis (PGD) of translocations with several methods, including telomeric probes. DESIGN: Retrospective study. SETTING: Clinical IVF laboratory. PATIENT(s): Thirty-five couples with one partner carrying a chromosomal translocation. INTERVENTION(s): PGD of translocation after polar-body or embryo biopsy. MAIN OUTCOME MEASURE(s): pregnancy outcome. RESULT(s): Several trends were observed. First, PGD can achieve a statistically significant reduction in spontaneous abortion, from 95% to 13%. Second, the chances of achieving pregnancy are correlated with 50% or more of the embryos being chromosomally normal. Third, patients with robertsonian translocations produced fewer abnormal gametes and more pregnancies than did patients with reciprocal translocations. Fourth, a new fluorescence in situ hybridization protocol for PGD of translocations, which involves applying telomeric probes, has proved adequately reliable with a 6% average error rate. CONCLUSION(s): PGD of translocations achieves a statistically significant reduction in spontaneous abortion, both for polar-body and blastomere biopsy cases. pregnancy outcome depended on the number of normal embryos available for transfer, with patients having <50% abnormal embryos achieving the most pregnancies. Because robertsonian translocations caused fewer abnormal embryos than reciprocal translocations, they also resulted in higher rates of implantation.- - - - - - - - - - ranking = 2keywords = abortion (Clic here for more details about this article) |
6/96. Subtle familial unbalanced translocation t(8;11)(p23.2;p15.5) in two fetuses with Beckwith-Wiedemann features.We describe a subtle translocation t(8;11)(p23.2;p15.5) ascertained after two induced abortions in the same sibship because of the discovery of fetal hydrops on ultrasound examination. Initial cytogenetic studies performed on cultured amniotic fluid cells were considered as normal in both fetuses. High resolution banding analysis and FISH studies performed on the parents' chromosomes revealed a paternal translocation t(8;11)(p23.2;p15.5). Retrospective FISH analysis of both fetuses showed that they carried the same chromosomal imbalance including a distal monosomy 8pter and a distal trisomy 11pter. The phenotypes of the fetuses were re-examined and found to be compatible with Beckwith-Wiedemann syndromes (BWS). FISH analysis using an IGF2 probe demonstrated the presence of three copies of the IGF2 gene. This study highlights the value of searching for subtle chromosome rearrangements in families with recurrent unexplained multiple malformation syndromes discovered prenatally. Also, it contributes to a better delineation of the prenatal phenotype of BWS. Finally, it sheds new light on the aetiology of non-immune hydrops fetalis.- - - - - - - - - - ranking = 1keywords = abortion (Clic here for more details about this article) |
7/96. Familial cryptic translocation with del 4q34-->qter and dup 12pter-->p13 in sibs with tracheal stenosis: clinical, classical and molecular cytogenetic studies and CGH analyses from archival placental tissues evidencing tertiary trisomy 4 in one abortion specimen.We report on two retarded half-sibs of different sex and seemingly normal karyotype who had the same syndrome of minor anomalies, heart defect and a distal tracheal stenosis, and who shared a healthy mother. These findings raised suspicions of a cryptic chromosome translocation. A translocation t(4;12)(q34;p13), balanced in the mother and unbalanced in the sibs with loss of terminal 4q and gain of terminal 12p regions, was verified by FISH using whole chromosome painting, subtelomeric and YAC probes. Clinical features could be explained by partial monosomy 4q and partial trisomy 12p. tracheal stenosis was interpreted as a consequence of the same developmental disturbance leading to esophageal atresia and tracheo-esophageal fistula. It was attributed to the 4q deletion in which esophageal atresia as also respiratory difficulties and airway obstructions had been described. paraffin-embedded placental tissues were available from three of the five abortions of the mother allowing DNA extraction and comparative genome hybridization (CGH). Two of the abortion specimens had the same der(4)t(4;12)(q34;p13) unbalanced translocation as identified in the sibs. In the third abortion specimen, suspicious of triploidy because of partial hydatidiform mole, CGH uncovered a tertiary trisomy 4 resulting from a 3:1 segregation of the translocation chromosomes and their homologs during maternal meiosis I. Differences in CGH results using DNA generated directly or after DOP-PCR were explained by dna fragmentation in paraffin-embedded tissues and unequal amplification. Am. J. Med. Genet. 94:271-280, 2000.- - - - - - - - - - ranking = 7keywords = abortion (Clic here for more details about this article) |
8/96. A de novo complex chromosomal rearrangement with a translocation 7;9 and 8q insertion in a male carrier with no infertility.A de novo complex chromosomal rearrangement (CCR) involving chromosomes 7, 8 and 9 in a male carrier was ascertained through his healthy wife's recurrent spontaneous abortions. Six pregnancies over eight years resulted in four spontaneous abortions and two livebirths who died perinatally due to abnormal vital signs. Cytogenetic analyses utilizing high resolution chromosome banding technique showed a deletion of band in a der(7) chromosome and an extra band inserting at 8q21.2. Another extra band was also observed at the band 9p24, but it could not be karyotypically determined. Fluorescent in-situ hybridization using chromosome 7 and 8 specific microdissected library as probes confirmed the insertion of a segment from the translocated chromosome 7 into a chromosome 8, and additionally revealed a translocation between chromosomes 7 and 9. The karyotype of the CCR carrier was determined as 46,XY,t(7;9)(q22;p24),ins(8;7)(q21.2;q22q32).ish der(9)(wcp7 );ins(8;7)(wcp8 ,wcp7 ). Comparing with previously reported male CCR carriers with our case, we conclude that male CCR carriers may not always present with infertility or subfertility phenotypes. This may suggest that rare transmission of male carriers could result from abnormal chromosomal rearrangements during meiosis and gametogenesis in addition to frequent infertility.- - - - - - - - - - ranking = 2keywords = abortion (Clic here for more details about this article) |
9/96. Interchromosomal insertions. Identification of five cases and a review.In five families with questionable chromosome rearrangements, we identified an interchromosomal insertion by fluorescent in situ hybridization (FISH). In case 1 with a dir ins (5;11)(p14;q14q24) in three generations, the mentally retarded and microcephalic proband showed a 5p14-->pter deletion. In case 2, a duplication (13)(q21.31--> q31.2) combined with a deletion (11)(q14-->q22) segregated from a reciprocal ins(11;13)(q14q122)(q21.32q31.2), causing a mixed phenotype with psychomotor retardation, caput quadratum, choanal atresia, and pes equinovarus. In case 3, a dir ins (18;5)(q21.3;p13.1p14) was associated with spontaneous abortions, in case 4, the proband with mental retardation, microcephaly, and a heart defect showed a pure trisomy of (12)(q13-->q15), which had segregated from a carrier of an ins (18;12)(p11.3;q13q15). In case 5, a duplication of (10)(q26.3-->q25.2) segregated from an inv ins(5;10)(q15;q26.3q25.2), which was passed on directly from a mother to her son,with mental retardation. In all families the elucidation of the insertional translocation (IT) considerably increased the associated genetic risks of carriers. For the review, we collected data from 81 articles on 87 IT probands on ascertainment, origin, familial transmittance, progeny, and genetic risks of IT carriers. We also discussed the recombinant chromosomes and complex rearrangements associated with ITs, and listed chromosome regions occurring solely as deletions, or solely as duplications, or as both to facilitate genotype/phenotype correlations. We conclude that ITs are rare chromosomal rearrangements with an 1:80,000 incidence, of which nearly 80% were referred because of congenital abnormalities and mental retardation. A maternal origin was seen in 59.5%, a paternal origin in 26.6%, and 13.9% were de novo. No notable difference in fertility between male and female IT carriers was noticed. Bias of ascertainment was excluded in 15 familial cases and led to an estimate of the genetic risks for IT carriers of 32.0-36.0%. The mean size of the inserted regions occurring solely as duplications (n=39) measures 0.96% of the haploid autosomal length (HAL), and of regions solely occurring as deletions (n=14) 0.47% HAL. In the families where both aneusomies occurred, the size of the insertions ranged between 0.22 and 1.21% HAL. overall, the findings fit with the general idea that a surplus of genetic material is tolerated more easily than a deficiency.- - - - - - - - - - ranking = 1keywords = abortion (Clic here for more details about this article) |
10/96. Case-specific, breakpoint-spanning dna probes for analysis of single interphase cells.Balanced reciprocal translocations are known to interfere with homolog pairing in meiosis. Many individuals carrying such chromosomal abnormalities suffer from reduced fertility or spontaneous abortions and seek help in the form of assisted reproductive technology. Although most translocations are relatively easy to detect in metaphase cells, the majority of embryonic cells biopsied in the course of in vitro fertilization (IVF) procedures are in interphase. These nuclei are, thus, unsuitable for analysis by chromosome banding or painting using fluorescence in situ hybridization (FISH). Our assay, based on FISH detection of breakpoint-spanning dna probes, identifies translocations in interphase nuclei by microscopic inspection of hybridization domains. Probes are selected that span the breakpoint regions on normal homologs. The probes should hybridize to several hundred kilobases of DNA flanking the breakpoint. The two breakpoint-spanning dna probes for the translocation chromosomes are labeled in separate colors (e.g., red and green). The translocation event producing two fused red/green hybridization domains can then be detected in interphase cell nuclei using a fluorescence microscope. We applied this scheme to analyze somatic and germ cells from 21 translocation patients, each with distinct breakpoints. Here, we summarize our experience and provide a description of strategies, cost estimates, as well as typical time frames.- - - - - - - - - - ranking = 1keywords = abortion (Clic here for more details about this article) |
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