45,X product of conception after preimplantation genetic diagnosis and euploid embryo transfer: evidence of a spontaneous conception confirmed by DNA fingerprinting.

BACKGROUND: Preimplantation genetic screening (PGS) provides an opportunity to eliminate a potential implantation failure due to aneuploidy in infertile couples. Some studies clearly show that twins following single embryo transfer (SET) can be the result of a concurrent natural conception and an incidence as high as 1 in 5 twins has been reported. In our case PGS was performed on trophectoderm (TE) biopsies by quantitative polymerase chain reaction (qPCR). The product of conception (POC) was cytogenetically investigated after selection of the placental villi by means of the direct method. Molecular cytogenetic characterization of the POC was performed by fluorescence in situ hybridization (FISH) and array-comparative genomic hybridization (a-CGH) analyses. To investigate the possibility of a spontaneous conception, a panel of 40 single nucleotide polymorphisms (SNPs) was used to compare genetic similarity between the DNA of the POC and the DNA leftover of the TE biopsy. FINDINGS: We describe a 36-year old infertile woman undergoing PGS who had a spontaneous abortion after a single euploid embryo transfer on a spontaneous cycle. The POC showed a 45,X karyotype confirmed by FISH and a-CGH. DNA fingerprinting demonstrated a genetic similarity of 75 % between the DNA of the POC and TE biopsy, consistent with a sibling status. All supernumerary euploid embryos were also tested showing a non-self relationship with the POC, excluding a mix-up event at the time of fetal embryo transfer. CONCLUSIONS: DNA fingerprinting of the transferred blastocyst and POC, confirmed the occurrence of a spontaneous conception. This case challenges the assumption that a pregnancy after assisted reproductive technology (ART) is always a result of ART, and strengthens the importance to avoid intercourses during PGS and natural transfer cycles. Moreover, cytogenetic analysis of the POCs is strongly recommended along with fingerprinting children born after PGS to see what the concordance is between the embryo transferred and the resultant child.

Genomic alterations in human umbilical cord-derived mesenchymal stromal cells call for stringent quality control before any possible therapeutic approach.

BACKGROUND AIMS: The umbilical cord (UC) is a promising source of mesenchymal stromal cells (MSCs). UC-MSCs display very similar in vitro characteristics to bone marrow-MSCs and could represent a valuable alternative for cell-based therapies. However, it is still unclear whether UC-MSCs are prone or not to the acquisition of genomic imbalances during in vitro expansion. METHODS: With the use of array-comparative genomic hybridization, we compared copy number variations of early (P2-P3) and late (>P5) passages of in vitro-expanded UC-MSCs. RESULTS: In two of 11 long-term UC-MSCs cultures, we observed the appearance of clones carrying genomic imbalances, which generated genetic mosaicism at intermediate passages. Although still able to reach the senescence phase, the cells carrying the genomic imbalance acquired a proliferative advantage, as demonstrated by the increase in frequency during long-term culture. CONCLUSIONS: Altogether, our results suggest that UC-MSC-based clinical protocols should be designed with caution; their clinical use should be preceded by array-comparative genomic hybridization screening for the acquisition of genomic imbalances during in vitro expansion.

Cell-cycle phases and genetic profile of bone marrow-derived mesenchymal stromal cells expanded in vitro from healthy donors.

Human mesenchymal stromal cells (MSCs) expanded in vitro for cell therapy approaches need to be carefully investigated for genetic stability, by employing both molecular and conventional karyotyping. Reliability of cytogenetic analysis may be hampered in some MSC samples by the difficulty of obtaining an adequate number of metaphases. In an attempt to overcome this problem, a methodology apt to evaluate the cell-cycle structure on synchronous MSCs was optimised. Results obtained in five independent experiments by comparing cell-cycle analysis of synchronous and asynchronous MSC populations evaluated at early and late culture passages documented that in synchronous MSCs, 30% of cells entered G2/M phase after about 27-28 h of culture, while in asynchronous MSCs only 8% of cells in G2/M phase could be observed at the same time point. Cytogenetic analysis on synchronous MSCs allowed us to obtain 20-25 valuable metaphases/slide, whereas only 0-4 metaphases/slide were detectable in asynchronous preparations.

Lung cancer in which the hypothesis of multi-step progression is confirmed by array-CGH results: A case report.

The pathogenesis of lung cancer has not been fully elucidated and biological markers acting as predictors of tumor evolution and aggressiveness remain unidentified. The multi-step hypothesis, suggesting a progression from adenomatous hyperplasia (AAH) to adenocarcinoma (AC) through bronchioalveolar carcinoma (BAC), was highlighted in a previous cytogenetic study performed in a single case. The present study reports the results of an array-comparative genomic hybridization (a-CGH) analysis performed on the DNA obtained from the previously reported case that presented AAH, BAC and AC in one lung. The a-CGH results confirm and support the previous cytogenetic observations with new data, clearly supporting the hypothesis of a multi-step carcinogenic process in the lung.

5p13 microduplication syndrome: a new case and better clinical definition of the syndrome.

Chromosome 5p13 duplication syndrome (OMIM #613174), a contiguous gene syndrome involving duplication of several genes on chromosome 5p13 including NIPBL (OMIM 608667), has been described in rare patients with developmental delay and learning disability, behavioral problems and peculiar facial dysmorphisms. 5p13 duplications described so far present with variable sizes, from 0.25 to 13.6 Mb, and contain a variable number of genes. Here we report another patient with 5p13 duplication syndrome including NIPBL gene only. Proband's phenotype overlapped that reported in patients with 5p13 microduplication syndrome and especially that of subjects with smaller duplications. Moreover, we better define genotype-phenotype relationship associated with this duplication and confirmed that NIPBL was likely the major dosage sensitive gene for the 5p13 microduplication phenotype.

MEF2C deletions and mutations versus duplications: a clinical comparison.

5q14.3 deletions including the MEF2C gene have been identified to date using genomic arrays in patients with severe developmental delay or intellectual disability, stereotypic behavior, epilepsy, cerebral malformations and a facial gestalt not really distinctive though characterized by broad and/or high, bulging forehead, upslanting palpebral fissures, flat nasal root and bridge, small, upturned nose, hypotonic small mouth resulting in cupid bow/tented upper lip. MEF2C mutations have been also identified in patients with overlapping phenotype so that it is considered the gene responsible for the 5q14.3 deletion syndrome. To date, one single duplication including MEF2C has been reported in a patient with intellectual disability but its clinical significance remains uncertain also because of the large size of the imbalance. Here we present two further patients with 5q14.3 duplications including MEF2C. Their phenotype indeed suggest the pathogenic effect of the MEF2C duplication although other duplicated genes also brain expressed might contribute to the clinical features. In none of them a clear-cut syndrome can be identified. A comparison between MEF2C deleted/mutated and duplicated patients is also presented.