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Biomedical subjects

Yury Verlinsky

Publications and source records attributed to Yury Verlinsky.

At least 37 records · Page 2Linked to original sources

Morula-derived human embryonic stem cells.

Human embryonic stem (ES) cells are known to derive from the inner cell mass of blastocyst. Although the embryos of other developmental stages have also been used as a source for ES cells in animal models, the feasibility of obtaining ES cell lines from human morula is not known, despite being an obvious source available through assisted reproduction and preimplantation genetic diagnosis programmes. This study describes an original technique for derivation of ES cells from human morula, which enabled the establishment of eight morula-derived ES cell lines. These ES cell lines were shown to have no morphological differences from the ES cells derived from blastocysts, and expressed the same ES cell specific markers, including Oct-4, tumour-resistance antigens TRA-2-39, stage-specific embryonic antigens SSEA-3 and SSEA-4, and high molecular weight glycoproteins TRA-1-60 and TRA-1-81, detected in the same colony of morula-derived ES cells showing specific alkaline phosphatase expression. No differences were observed in these marker expressions in the morula-derived ES cells cultured in the feeder layer free medium. Similar to ES cell originating from blastocyst, the morula-derived ES cells were shown to spontaneously differentiate in vitro into a variety of cell types, including the neuron-like and contracting primitive cardiocyte-like cells.

Biomarkers↗

Preimplantation HLA typing and stem cell transplantation: report of International Meeting, Cyprus, 27-8 March, 2004.

There has been progress in the application of stem cell transplantation for the treatment of an increasing number of severe congenital and acquired bone marrow disorders that are currently restricted by the availability of human leukocyte antigen(HLA)-matched related donors. Preimplantation HLA typing has recently been introduced to improve the access to stem cell therapy for inherited bone marrow failures, and its possible use for the treatment of common sporadic malignant and non-malignant bone marrow disorders has also been explored. This paper describes the current experience of preimplantation HLA typing, reviewed by the International Meeting on the subject, which includes preimplantation HLA typing in 147 cycles, 109 of which were carried out as part of preimplantation genetic diagnosis (PGD) for Fanconi anaemia, thalassaemia, Wiscott-Aldrich syndrome, hyperimmunoglobulin M syndrome, hypohidrotic ectodermal dysplasia with immune deficiency, and X-linked adrenoleukodystrophy, and 38 for the sole purpose of HLA typing for leukaemias and aplastic and Diamond-Blackfan anaemias. The applied method resulted in the accurate pre-selection and transfer of HLA-matched embryos, yielding 25 clinical pregnancies and the birth of 14 HLA-matched children to the siblings who required stem cell transplantation.

Bioethics↗

Preimplantation genetic diagnosis with HLA matching.

Preimplantation genetic diagnosis (PGD) has recently been offered in combination with HLA typing, which allowed a successful haematopoietic reconstitution in affected siblings with Fanconi anaemia by transplantation of stem cells obtained from the HLA-matched offspring resulting from PGD. This study presents the results of the first PGD practical experience performed in a group of couples at risk for producing children with genetic disorders. These parents also requested preimplantation HLA typing for treating the affected children in the family, who required HLA-matched stem cell transplantation. Using a standard IVF procedure, oocytes or embryos were tested for causative gene mutations simultaneously with HLA alleles, selecting and transferring only those unaffected embryos, which were HLA matched to the affected siblings. The procedure was performed for patients with children affected by Fanconi anaemia (FANC) A and C, different thalassaemia mutations, Wiscott-Aldrich syndrome, X-linked adrenoleukodystrophy, X-linked hyperimmunoglobulin M syndrome and X-linked hypohidrotic ectodermal displasia with immune deficiency. Overall, 46 PGD cycles were performed for 26 couples, resulting in selection and transfer of 50 unaffected HLA-matched embryos in 33 cycles, yielding six HLA-matched clinical pregnancies and the birth of five unaffected HLA-matched children. Despite the controversy of PGD use for HLA typing, the data demonstrate the usefulness of this approach for at-risk couples, not only to avoid the birth of affected children with an inherited disease, but also for having unaffected children who may also be potential HLA-matched donors of stem cells for treatment of affected siblings.

Adrenoleukodystrophy↗

Preimplantation genetic diagnosis for the Kell genotype.

OBJECTIVE: To use preimplantation genetic diagnosis (PGD) to achieve a Kell 1 (K1) allele-free pregnancy in couples at risk for producing a child with hemolytic disease of the newborn (HDN) caused by maternofetal incompatibility in sensitized mothers. DESIGN: DNA analysis of biopsied blastomeres from cleavage-stage embryos in IVF-ET with the goal of identifying and transferring back to patients the K1 allele-free embryos. SETTING: IVF program at the Reproductive Genetics Institute, Chicago, Illinois, and IVF Michigan, Rochester Hills, Michigan. PATIENT(S): Two at-risk couples with a history of neonatal death caused by HDN due to K1/K2 genotype in a male partner. INTERVENTION(S): Biopsy of single blastomeres and testing for paternal K1 allele in each embryo after standard IVF. MAIN OUTCOME MEASURE(S): DNA analysis of blastomeres indicating whether corresponding embryos were K1 allele-free for the purpose of transferring only embryos without the K1 allele. RESULT(S): Of 36 embryos tested in five cycles from two couples, 18 were predicted to be K1 allele-free. Of these, 9 were transferred, resulting in a K1 allele-free twin pregnancy and the birth of two healthy children. CONCLUSION(S): PGD of the K1 genotype resulted in the birth of healthy twins confirmed to be free of the K1 allele. PGD in couples with a heterozygous K1/K2 male partner provides an option for avoiding HDN in sensitized mothers.

Adult↗

Current status of preimplantation diagnosis for single gene disorders.

Preimplantation genetic diagnosis (PGD) has become an established procedure for avoiding the birth of affected children with single gene disorders. PGD is performed through polar body or blastomere biopsy, which has no deleterious effect on pre- and post-implantation development. This review describes the most recent developments and current changes in the spectrum of conditions for which PGD has been applied. The most recent applications of PGD include congenital malformations, blood group incompatibility and an increasing number of late onset disorders with genetic predisposition, all of which have not previously been diagnosed using PGD. Despite ethical concerns, PGD has also been used for preselection of unaffected and HLA matched embryos, and recently for preimplantation HLA matching without testing for the causative gene. This extends the practical value of PGD, with its utility being no longer limited to prevention of single gene disorders, by expanding it to treatment of siblings requiring stem cell transplantation.

Fertilization in Vitro↗

Is there any predictive value of first polar body morphology for embryo genotype or developmental potential?

The first polar body (PB1) was previously used for genotyping oocytes in preimplantation genetic diagnosis (PGD) for Mendelian and chromosomal disorders. A possible use of PB1 morphology for predicting developmental potential was also explored in a few retrospective studies, which showed controversial results. PB1 morphology was evaluated in a prospective study of 831 oocytes, which were then followed up through preimplantation development, with analysis of fertilization rate, embryo quality, survival to blastocyst, and outcome of embryo transfer, demonstrating no correlation with PB1 morphology. There was also no evidence for a PB1 predictive value for these parameters either in good or poor responder patients. An additional 358 oocytes and embryos from patients requesting PGD were tested for aneuploidies, revealing no relationship with PB1 morphology either. This suggests that PB1 morphology may not be a reliable predictor of genotype or the developmental potential of the corresponding oocytes or embryos.

Aneuploidy↗

The role of preimplantation genetic diagnosis in women of advanced reproductive age.

PURPOSE OF REVIEW: More than half of in-vitro fertilization patients are of advanced reproductive age and at risk for producing offspring with age-related aneuploidies, which contribute significantly to spontaneous abortions and implantation failure. RECENT FINDINGS: Fluorescent in-situ hybridization analysis of thousands of oocytes and preimplantation embryos obtained from these patients revealed an aneuploidy rate of over 50%, suggesting practical relevance of preimplantation genetic diagnosis for aneuploidy to women of advanced reproductive age. The overall preimplantation genetic diagnosis experience for age-related aneuploidies comprising more than 3000 clinical cycles indicates the positive impact of preselection and transfer of aneuploidy-free embryos on implantation and pregnancy rates and outcome of pregnancies in women of advanced reproductive age. SUMMARY: These patients will need to be informed about preimplantation genetic diagnosis availability, in order use this option to improve their relatively poor chances of becoming pregnant, especially with the current tendency of limiting the number of transferred embryos to avoid complications due to multiple pregnancies. This may contribute significantly to improving standards of assisted reproduction technology, substituting the current practice of selection of embryos for transfer using morphological parameters with the preselection of aneuploidy-free embryos with a higher potential to result in pregnancy.

Adult↗

Preimplantation diagnosis for early-onset Alzheimer disease caused by V717L mutation.

CONTEXT: Indications for preimplantation genetic diagnosis (PGD) have recently been expanded to include disorders with genetic predisposition to allow only embryos free of predisposing genes to be preselected for transfer back to patients, with no potential for pregnancy termination. OBJECTIVE: To perform PGD for early-onset Alzheimer disease (AD), determined by nearly completely penetrant autosomal dominant mutation in the amyloid precursor protein (APP) gene. DESIGN: Analysis undertaken in 1999-2000 of DNA for the V717L mutation (valine to leucine substitution at codon 717) in the APP gene in the first and second polar bodies, obtained by sequential sampling of oocytes following in vitro fertilization, to preselect and transfer back to the patient only the embryos that resulted from mutation-free oocytes. SETTING: An in vitro fertilization center in Chicago, Ill. PATIENTS: A 30-year-old AD-asymptomatic woman with a V717L mutation that was identified by predictive testing of a family with a history of early-onset AD. MAIN OUTCOME MEASURES: Results of mutation analysis; pregnancy outcome. RESULTS: Four of 15 embryos tested for maternal mutation in 2 PGD cycles, originating from V717L mutation--free oocytes, were preselected for embryo transfer, yielding a clinical pregnancy and birth of a healthy child free of predisposing gene mutation according to chorionic villus sampling and testing of the neonate's blood. CONCLUSION: This is the first known PGD procedure for inherited early-onset AD resulting in a clinical pregnancy and birth of a child free of inherited predisposition to early-onset AD.

Adult↗

Preimplantation diagnosis for diseases with genetic predisposition and nondisease testing.

Preimplantation genetic diagnosis has become a method of choice in genetic practices. The present experience includes thousands of clinical cases of preimplantation genetic diagnosis, demonstrating the safety, accuracy and reliability of the technique and its clinical relevance for those at-risk couples who cannot accept traditional methods for prenatal diagnosis and termination of pregnancy. Most recently, preimplantation genetic diagnosis has been performed for late-onset disorders, such as genetic predisposition to cancers, Alzhelmer's disease and nondisease testing involving human leukocyte antigen typing, never practiced in prenatal diagnosis. The review of these developments suggests the clinical usefulness of this new approach for avoiding the birth of children with genetic predisposition to cancers and other late-onset disorders, or preimplanation human leukocyte antigen matching to provide the treatment of the affected siblings requiring bone marrow transplantation.

Alzheimer Disease↗

Preimplantation diagnosis for long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency.

Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency is a fatal autosomal recessive metabolic disorder, presenting during infancy. Preimplantation genetic diagnosis (PGD) provides an option for establishing an unaffected pregnancy, avoiding the risk for termination of pregnancy following prenatal diagnosis. The method for pre-selection of mutation-free oocytes for LCHAD deficiency was developed by testing the first and second polar body removed from oocytes by micromanipulation techniques in the framework of in-vitro fertilization. To avoid misdiagnosis, testing was done using hemi-nested polymerase chain reaction (PCR), with outer primers designed to lie outside the pseudogene, eliminating false priming. Four of 12 tested oocytes were predicted to be unaffected, based on the heterozygous first and mutant second polar body. The embryos resulting from these mutation-free oocytes were replaced, yielding a singleton clinical pregnancy and birth of a healthy child following confirmation by prenatal diagnosis.

Journal Article↗

Preimplantation diagnosis for p53 tumour suppressor gene mutations.

Preimplantation genetic diagnosis (PGD) was introduced for high-risk couples to avoid establishing affected pregnancies potentially requiring termination following prenatal diagnosis. This opens the possibility for PGD for late onset disorders with genetic predisposition, including inherited cancer predisposition, because only embryos free from the predisposing gene may be transferred back to the patient, with no potential risk for pregnancy termination. PGD was performed for two couples, one with maternally and one with paternally derived p53 tumour-suppressor mutations, 902insC in exon 8 and G524A in exon 5, respectively. This involved a standard IVF protocol, allowing oocytes or embryos to be tested prior to their transfer back to uterus. Maternal mutation was tested by sequential PCR analysis of the first and second polar bodies, removed following maturation and fertilization of oocytes, while paternal mutation analysis required embryo biopsy at the cleavage stage. To avoid misdiagnosis due to allele drop out, multiplex nested PCR was applied, involving p53 mutation analysis simultaneously with the linked short tandem repeats in intron 1. Of 10 oocytes tested in two PGD cycles for 902insC mutation, four unaffected oocytes were pre-selected for transfer yielding no clinical pregnancy. Of 18 embryos analysed in two cycles for G524A mutation, seven mutation-free embryos were detected, two of which were transferred in each cycle, resulting in a singleton pregnancy and birth of a mutation-free child. This is the first PGD for inherited cancer predisposition determined by p53 tumour suppressor mutations, resulting in a clinical pregnancy and birth of a child free from inherited cancer predisposition.

Journal Article↗

Preimplantation genetic diagnosis for cancer predisposition.

Preimplantation genetic diagnosis (PGD) has recently been offered for couples with an inherited predisposition for late onset disorders. This paper presents the results of PGD for a group of couples at risk for producing children with cancer predisposition. Using a standard IVF procedure, oocytes or embryos were tested for different mutations predisposing to cancer, preselecting and transferring only mutation-free embryos back to the patients. The procedure was performed for patients with predisposition to familial adenomatous polyposis coli (FAP), Von Hippel-Lindau syndrome (VHL), retinoblastoma, Li-Fraumeni syndrome, determined by p53 tumour suppressor gene mutations, neurofibromatosis types I and II and familial posterior fossa brain tumour (hSNF5). Overall, 20 PGD cycles were performed for 10 couples, resulting in preselection and transfer of 40 mutation-free embryos, which resulted in five unaffected clinical pregnancies and four healthy children born by the present time. Despite the controversy of PGD use for late onset disorders, the data demonstrate the usefulness of this approach as the only acceptable option for at-risk couples to avoid the birth of children with an inherited predisposition to cancer, and to have a healthy child.

Adenomatous Polyposis Coli↗

Preimplantation diagnosis for neurofibromatosis.

Preimplantation genetic diagnosis (PGD) has recently been performed for inherited cancer predisposition determined by p53 tumour suppressor gene mutations, suggesting the usefulness of PGD for late onset disorders with genetic predisposition, including those caused by the germline mutations of other tumour suppressor genes. Here PGD was performed for two couples, one at risk for producing a child with maternally derived neurofibromatosis type I (NF1), and the other with paternally derived neurofibromatosis type II (NF2). The procedure involved a standard IVF protocol, combined with testing of oocytes or embryos prior to their transfer back to the patients. Maternal mutation Trp-->Ter (TGG-->TGA) in exon 29 of the NF1 gene was tested by sequential PCR analysis of the first and second polar bodies, and paternal L141P mutation in exon 4 of the NF2 gene by embryo biopsy at the cleavage stage. In both cases, multiplex nested PCR was applied, involving NF1 and NF2 mutation analysis simultaneously with the 3 and 2 linked markers, respectively. Of 57 oocytes tested in four PGD cycles for NF1 mutation, 26 mutation-free oocytes were detected, from which eight were preselected for transfer, two in each cycle. These produced two clinical pregnancies, one confirmed to be mutation free by chorionic villus sampling but ending in a stillbirth, and the other still ongoing. Of 18 embryos analysed in a cycle performed for NF2 mutation, eight mutation-free embryos were detected, three of which were transferred back to the patient, resulting in a singleton pregnancy and the birth of a mutation-free child. This suggests that PGD is a useful approach for avoiding the birth of children with inherited cancer predisposition, determined by NF1 and NF2 gene mutations.

Adult↗

Current features of preimplantation genetic diagnosis.

More than 4000 preimplantation genetic diagnosis (PGD) cycles have been performed, suggesting that PGD may no longer be considered a research activity. The important present feature of PGD is its expansion to a variety of conditions, which have never been considered as an indication for prenatal diagnosis, including the late-onset disorders with genetic predisposition and preimplantation non-disease testing, with the further improvement of the accuracy of PGD for single gene disorders. PGD has also become a useful tool for the improvement of the effectiveness of IVF, through avoiding the transfer of chromosomally abnormal embryos, representing more than half of the embryos routinely transferred in IVF patients of advanced maternal age and other poor prognosis patients. PGD is of particular hope for the carriers of balanced chromosomal translocations, as it allows accurate pre-selection of a few balanced or normal embryos resulting from the extremely poor meiotic outcome, especially in reciprocal translocations. With the current progress in polymerase chain reaction- (PCR-) based detection of chromosomal abnormalities in oocytes and embryos, PGD may soon be performed for both chromosomal and single gene disorders using the same biopsied polar body or blastomere, frequently required with the currently expanded PGD application. The available clinical outcome data of more than 3000 PGD embryo transfers further suggest an acceptable pregnancy rate and safety of the procedure, as demonstrated by the follow-up information available for more than 500 children born from these PGD transfers.

Chromosome Aberrations↗

Nuclear transfer for full karyotyping and preimplantation diagnosis for translocations.

Preimplantation genetic diagnosis (PGD) for chromosomal disorders is currently performed by interphase fluorescence in-situ hybridization (FISH) analysis. This technique is known to have limitations for detecting some translocations and complete karyotyping, so visualization of chromosomes in single cells is required to improve the PGD accuracy for chromosomal disorders. To achieve this, single blastomeres were fused with enucleated or intact mouse zygotes, followed by fixing the resulting heterokaryons at the metaphase of the first cleavage division, or treating them with okadaic acid to induce premature chromosome condensation. This method allowed a significant improvement in the accuracy of testing both maternally- and paternally-derived translocations. In all, 437 blastomeres were tested, achieving full karyotyping in as many as 383 (88%), making it possible to pre-select only normal embryos or those with balanced chromosomal complements for transfer. Overall, PGD for translocations was applied in 94 clinical cycles, resulting in 66 transfers and 20 (30.3%) clinical pregnancies, with healthy deliveries of 15 children. Fifty-two of these cycles were performed using a nuclear transfer (conversion) technique, which resulted in 38 transfers of balanced or normal embryos, demonstrating that the technique is accurate and reliable for karyotyping single blastomeres for PGD of translocations.

Animals↗