Recurrent IVF failure, implantation failure and early embryo demise can be attributed to the high frequency of chromosomal aneuploidy observed in human embryos. Preimplantation genetic screening (PGS) using multiple displacement amplifications (MDA) and array comparative genomic hybridization (aCGH) was successfully performed on eight patients with a minimum of seven recurrent IVF failures with the aim of detecting aneuploidy and ameliorating pregnancy rate. A total of 41 embryos with eight or more cells were biopsied by taking two blastomeres from each embryo. The DNA from these blastomeres were amplified and analysed by aCGH technology. The aCGH results showed a complex panel of chromosomal abnormalities in 60% of the diagnosed embryos. Some abnormalities could not be detected by the seven-probe panel (13, 16, 18, 21, 22, X and Y) used in fluorescence in-situ hybridization. Six out of eight patients had embryos for transfer with five out of those six showing positive pregnancy tests. As far as is known, this report is the first to show a pregnancy after PGS using the aCGH technology. The pregnancy rate obtained here is encouraging and will open the door for enrollment of more patients.

Multiple displacement amplification (MDA) is a technique used in the amplification of very low amounts of DNA and reported to yield large quantities of high-quality DNA. We used MDA to amplify the whole genome directly from a single cell. The most common techniques used in PGD are PCR and fluorescent in-situ hybridization (FISH). There are many limitations to these techniques including, the number of chromosomes diagnosed for FISH or the quality of DNA issued from a single cell PCR. This report shows, for the first time, use of MDA for single cell whole genome amplification. A total of 16 short tandem repeats (STRs) were amplified successfully with a similar pattern to the genomic DNA. Furthermore, allelic drop out (ADO) derived from MDA was assessed in 40 single cells by analysing (i) heterozygosity for a known beta globin mutation (IVSI-5 C-G) and by studying (ii) the heterozygous loci present in the STRs. ADO turned out to be 10.25% for the beta globin gene sequencing and 5% for the fluorescent PCR analysis of STRs. Moreover, the amplification accuracy of MDA permitted the detection of trisomy 21 on a single cell using comparative genome hybridization-array. Altogether, these data suggest that MDA can be used for single cell molecular karyotyping and the diagnosis of any single gene disorder in PGD.

Background: Human origins and migration models proposing the Horn of Africa as a prehistoric exit route to Asia have stimulated molecular genetic studies in the region using uniparental loci. However, from a Y-chromosome perspective, Saudi Arabia, the largest country of the region, has not yet been surveyed. To address this gap, a sample of 157 Saudi males was analyzed at high resolution using 67 Y-chromosome binary markers. In addition, haplotypic diversity for its most prominent J1-M267 lineage was estimated using a set of 17 Y-specific STR loci.

Time-lapse imaging morphokinetics may play a role in early prediction of aneuploid embryos due to differences in kinetic behavior that may aid in improving clinical outcome.

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