Live birth after PGD with confirmation by a comprehensive approach (karyomapping) for simultaneous detection of monogenic and chromosomal disorders.

Preimplantation genetic diagnosis (PGD) for monogenic disorders has the drawback of time and cost associated with tailoring a specific test for each couple, disorder, or both. The inability of any single assay to detect the monogenic disorder in question and simultaneously the chromosomal complement of the embryo also limits its application as separate tests may need to be carried out on the amplified material. The first clinical use of a novel approach ('karyomapping') was designed to circumvent this problem.

Human preimplantation embryo development in vitro: a morphological assessment of sibling zygotes cultured in a single medium or in sequential media.

A comparison was made of the development of human zygotes in either a one-step (Global® medium) or two-step culture system (Quinn's Advantage®). A total of 257 normally fertilized 2PN zygotes from 28 patients were used in the study. The study was broken down into two parts: the first concerned the development of embryos from Days 1 to 3 in Global® medium and Quinn's Advantage® cleavage medium; the second consisted of a comparison of the development of embryos from Day 3 to 5/6 in Global® medium and Quinn's Advantage® blastocyst medium.

Molecular origin of female meiotic aneuploidies.

Chromosome aneuploidy is a major cause of pregnancy loss, abnormal pregnancy and live births following both natural conception and in vitro fertilisation (IVF) and increases exponentially with maternal age in the decade preceding the menopause. Molecular genetic analysis has shown that these are predominantly maternal in origin and trisomies most frequently occur through errors in the first meiotic division. Analysis of chromosome copy number in the three products of female meiosis, the first and second polar bodies and the corresponding zygote by microarray comparative genomic hybridisation (array CGH), in women of advanced maternal age undergoing IVF, has recently revealed a pattern of frequent multiple meiotic errors, caused by premature predivision of sister chromatids in meiosis I and a high incidence of errors in meiosis II.

Multiple meiotic errors caused by predivision of chromatids in women of advanced maternal age undergoing in vitro fertilisation.

Chromosome aneuploidy is a major cause of pregnancy loss, abnormal pregnancy and live births following both natural conception and in vitro fertilisation (IVF) and increases exponentially with maternal age in the decade preceding the menopause. Molecular genetic analysis following natural conception and spontaneous miscarriage demonstrates that trisomies arise mainly in female meiosis and particularly in the first meiotic division. Here, we studied copy number gains and losses for all chromosomes in the two by-products of female meiosis, the first and second polar bodies, and the corresponding zygotes in women of advanced maternal age undergoing IVF, using microarray comparative genomic hybridisation (array CGH).

PGD and aneuploidy screening for 24 chromosomes by genome-wide SNP analysis: seeing the wood and the trees.

Bisignano et al. (2011) argue that, for preimplantation genetic diagnosis (PGD) of aneuploidy for all 24 chromosomes, microarray-based comparative genomic hybridization (array CGH) is superior to the use of single-nucleotide polymorphism (SNP) genotyping arrays. Published studies indicate that both technologies accurately detect aneuploidy of whole chromosomes or chromosome segments.

Preimplantation genetic diagnosis after 20 years.

Preimplantation genetic diagnosis (PGD) should not be an option only for the few couples at risk of serious genetic conditions who can afford it. We appear to have lost sight of the original driving force behind the development of PGD, which is that most couples who carry a serious genetic disorder find it more acceptable to choose to conceive with healthy embryos tested in-vitro at preimplantation stages of development within the first week following fertilization, even if that means discarding those diagnosed as affected. It has been shown using cystic fibrosis as an example, that the cost savings to the US healthcare system of providing free IVF-PGD to all carrier couples compared to the lifetime costs of medical treatment for patients affected by this disease, run to dozens of billions of dollars.

Scoring of sperm chromosomal abnormalities by manual and automated approaches: qualitative and quantitative comparisons.

It is now well known that levels of sperm disomy correlate to levels of infertility (as well as other factors). The risk of perpetuating aneuploidy to the offspring of infertile males undergoing intracytoplasmic sperm injection (ICSI) has become a hotly debated issue in assisted reproduction; however, there remain barriers to the practical implementation of offering sperm disomy screening in a clinical setting. The major barrier is the operator time taken to analyze a statistically meaningful (sufficient) number of cells.

Karyomapping: a universal method for genome wide analysis of genetic disease based on mapping crossovers between parental haplotypes.

The use of genome wide single nucleotide polymorphism (SNP) arrays for high resolution molecular cytogenetic analysis using a combination of quantitative and genotype analysis is well established. This study demonstrates that by Mendelian analysis of the SNP genotypes of the parents and a sibling or other appropriate family member to establish phase, it is possible to identify informative loci for each of the four parental haplotypes across each chromosome and map the inheritance of these haplotypes and the position of any crossovers in the proband. The resulting 'karyomap', unlike a karyotype, identifies the parental and grandparental origin of each chromosome and chromosome segment and is unique for every individual being defined by the independent segregation of parental chromosomes and the pattern of non-recombinant and recombinant chromosomes.

The centrosome and early embryogenesis: clinical insights.

In humans and most mammals, with the exception of some rodents notably the mouse, the centrosome, which is the organizing centre of the spindle, is uniparentally (paternally) inherited. The sperm centrosome is transmitted to the egg at fertilization, forming an aster comprising radially arrayed microtubules that brings the male and female pronuclei into close apposition and organizes the first mitotic spindle in the zygote. Each centrosome contains a pair of centrioles that are oriented perpendicular to one another, surrounded by dense fibrillar pericentriolar material, within which functional and regulatory molecules are embedded.

Polycystic ovary syndrome: a transgenerational evolutionary adaptation.

Polycystic ovary syndrome has a common association with anovulatory infertility, while the physical symptoms are often associated with the increased androgens that are part of the endocrine profile. There is a well-recognised association with lipid and glucose metabolism anomalies and, when undergoing ovulation induction, ovarian hyperstimulation syndrome. This common condition is familial, but a contributory gene has yet to be found.

Is the sperm centrosome to blame for the complex polyploid chromosome patterns observed in cleavage stage embryos from an OAT patient?

Oligoasthenoteratozoospermia (OAT) is defined by a combined low count < 20 x 10(6) sperm/ml, poor motility < 50 % forward progression or < 25 % rapid linear progression and abnormal morphology (5-8 % normal using Kruger strict criteria) and has been associated with increased levels of sperm aneuploidy. Here we report on the cytogenetic findings from three 'spare' embryos from a couple that were referred for ICSI because of OAT. The embryos were processed for sequential FISH in three hybridization rounds using probes for chromosomes 3, 7, 9, 13, 17, 18, 21, X and Y.

Paternal inheritance of a 16qh-polymorphism in a patient with repeated IVF failure.

Polymorphisms of the size of heterochromatic centromeric regions of chromosomes have been well documented in the human. They appear to have no phenotypic effects in the carriers. However, they appear to be over-represented in infertile couples and those with repeated miscarriages, and there is now growing evidence that they are involved in meiotic pairing, spindle fibre attachment and chromosome movement.

Rupture of tubal pregnancy in the Vilnius population.

Objectives: To evaluate the determinants of tubal rupture in women who suffered from ectopic pregnancy in relation to their demographic profile and medical history.

Study Design: This retrospective observational clinical study was conducted in five general hospitals in Vilnius, Lithuania. The population was composed of 879 women with surgically proven ectopic pregnancy.

Comparison of effects of zona drilling by non-contact infrared laser or acid Tyrode's on the development of human biopsied embryos as revealed by blastomere viability, cytoskeletal analysis and molecular cytogenetics.

Use of a non-contact infrared laser (IRL) or acid Tyrode's for zona drilling before embryo biopsy was compared by assessing blastomere viability using various fluorescent markers or culture of the single biopsied blastomere, and, by cytoskeletal and molecular cytogenetic analysis of the biopsied embryos following culture to the blastocyst stage. There was no significant difference in the proportion of biopsied embryos that showed no damage in both the biopsied blastomere and in the remaining embryo (acid Tyrode's: 75% versus IRL: 68%), or in the proportion of single biopsied blastomeres that divided in culture (P > 0.05).

Spindle abnormalities in normally developing and arrested human preimplantation embryos in vitro identified by confocal laser scanning microscopy.

Background: Despite recent technical improvements, many human preimplantation embryos fail to develop to the blastocyst stage or implant after transfer to the uterus. A possible cause for this developmental arrest is the high incidence of nuclear and postzygotic chromosomal abnormalities observed during cleavage, including chaotic chromosome complements, suggestive of defects in mitotic chromosomal segregation. The underlying mechanisms are largely unknown, but similarities with chromosome instability in human cancers led to the proposal that cell cycle checkpoints may not operate at these early stages.