First experience of hematopoietic stem cell transplantation treatment of Shwachman-Diamond syndrome using unaffected HLA-matched sibling donor produced through preimplantation HLA typing.

The only proven cure for Shwachman-Diamond syndrome (SDS) bone marrow failure is allogeneic hematopoietic stem cell transplantation (HSCT). However HSCT with donors other than HLA-identical siblings is associated with high mortality and unfavorable prognosis. This paper presents the first experience of HSCT treatment of SDS using an unaffected HLA-identical sibling produced through preimplantation genetic diagnosis (PGD). The patient was a 6-year-old blood transfusion-dependent SDS baby girl with secondary myelodysplastic syndrome, for whom no HLA-identical donor was available. As a result of PGD, two unaffected HLA matched embryos were identified; one of them was randomly selected for transfer, resulting in a clinical pregnancy and birth of an apparently healthy child. The patient underwent allogeneic transplantation of cord blood hematopoietic stem cells, together with bone marrow from this sibling, resulting in complete hemopoietic recovery. The patient was no longer transfusion-dependent and had normal blood values 160 days after transplantation.

[THE LABORATORY MARKERS OF DETECTION OF BETA-THALASSEMIA CARRIAGE].

The article presents the results of examination of 110 patients (57 males and 53 females aged from 2 to 58 years) with microcytic hypochromic anemia. The kit of laboratory markers comprised hematological parameters (MCV, Metzer Index), biochemical (serum iron, ferritin), electrophoresis data (Hb, A2, Hb F) and molecular genetic analysis data (mutations of beta-globin gene). The application of this kit permitted to detected and to prove carriage of thalassemia шт 70 out of 110 patients with microcytic anemia. The proposed markers' kit can be applied in screening programs and in differential diagnostic of agents of beta-thalassemia and patients with iron-deficiency anemia.

Repository of human embryonic stem cell lines and development of individual specific lines using stembrid technology.

A human embryonic stem cell (HESC) line repository has been established, containing HESC lines with normal and abnormal genotypes, providing the source for studying the primary mechanisms of genetic disorders at the cellular level. Because the outcome of HESC transplantation treatment depends on access to human leukocyte antigen identical stem cells, the development of individual specific HESC was initiated, using the original stembrid technology, which is based on the hybridization of adult somatic cells with cytoplast of HESC lines. The data presented here demonstrate feasibility of this approach in the future development of HESC transplantation treatment of genetic and acquired disorders. The established HESC repository presently contains 166 HESC lines, including 127 with normal genotype and 39 with genetic and chromosomal disorders.

Preimplantation diagnosis and HLA typing for haemoglobin disorders.

Haemoglobin disorders are among the most frequent indications for preimplantation genetic diagnosis (PGD), introduced as an important option to couples at risk for producing offspring with thalassaemia and sickle cell disease. Previous experience mainly included PGD for beta-thalassaemia, while PGD for alpha-thalassaemia resulting in an unaffected pregnancy has not been reported. This study presents the results of the world's largest experience of 197 PGD cycles for haemoglobin disorders, which includes PGD for alpha-thalassaemia, resulting in 53 clinical pregnancies and birth of 45 healthy children, with five still ongoing. Fifty-four of these cycles were performed in combination with HLA typing, allowing the birth of thalassaemia-free children who were also HLA identical to the affected sibling, with successful stem cell transplantation in one case. As an increasing proportion of patients requesting PGD with HLA typing are of advanced reproductive age, aneuploidy testing was performed simultaneously with PGD. The results show that PGD has now become a practical approach for prevention of haemoglobin disorders, and is gradually being used also for improving access to HLA compatible stem cell transplantation for this group of diseases.

Human embryonic stem cell lines with genetic disorders.

A previous study described the establishment of human embryonic stem cell (ESC) lines from different sources of embryonic material, including morula, whole blastocyst and isolated inner cell mass. Using these methods, a repository of ESC lines has been established with different genetic abnormalities, which provides an unlimited source of disease cells in culture for undertaking research on the primary disturbances of the cellular processes in the genetically abnormal cells. ESC lines with genetic disorders were derived from the mutant embryos detected and avoided from transfer in the ongoing practice of preimplantation genetic diagnosis (PGD). The current repository contains 18 ESC lines with genetic disorders, including adrenoleukodystrophy, Duchenne and Becker muscular dystrophy, Fanconi anaemia, complementation group A, fragile-X syndrome, Huntington disease (three lines), Marfan syndrome, myotonic dystrophy (two lines), neurofibromatosis type I (five lines) and thalassaemia (two lines). These ESC lines are presently used for research purposes and may be available on request.

Preimplantation genetic diagnosis for early-onset torsion dystonia.

Early-onset primary torsion dystonia (DYT1) is the most severe and common form of hereditary movement disorders, characterized by sustained twisting contractures that begin in childhood, which is caused in majority of cases by a 3-bp deletion of the DYT1 gene on chromosome 9q34 at the heterozygote state. As there is no effective treatment of this disease, preimplantation genetic diagnosis (PGD) may be a useful option for at-risk couples to establish an DYT1 mutation-free pregnancy. PGD was performed for two obligate carriers of the DYT1 3-bp deletion, using blastomere testing to preselect the mutation-free embryos, based on mutation analysis with simultaneous testing of the three closely linked markers, D9S62, D9S63 and ASS. Of 19 tested blastomeres in three cycles, 17 had conclusive information about the mutation and linked markers, of which eight were predicted to be free of 3-bp deletion. Six of these embryos were transferred back to patients, two in each cycle, yielding singleton DYT1 3-bp deletion-free clinical pregnancies in two. One of these pregnancies was terminated due to severe anencephaly and the other resulted in birth of a mutation-free child. This is the first PGD for primary torsion dystonia, providing an alternative for those at-risk couples who cannot accept prenatal diagnosis and termination of pregnancy as an option for avoiding early onset torsion dystonia.

Preimplantation genetic diagnosis for familial dysautonomia.

Familial dysautonomia (FD) is the most common congenital sensory neuropathy in Ashkenazi Jews, caused by a single major mutation in the IKBKAP gene. Effective management for this severe debilitating disease is still not available, making preimplantation genetic diagnosis (PGD) a useful option for at-risk couples to establish an FD free pregnancy from the outset. PGD was performed for a couple with a previous affected child with FD, using first and second polar body testing to preselect mutation-free oocytes, based on mutation analysis with simultaneous testing of two closely linked markers, D9S58 and D9S1677. Of 15 tested oocytes, 11 carried information about both polar bodies' genotype, of which seven were predicted to be free of the FD gene. Three embryos resulting from these oocytes were transferred back to the patient, resulting in a triplet pregnancy and the birth of three unaffected children confirmed to be free of FD. This is the first PGD for FD, providing an alternative for those at-risk couples who cannot accept prenatal diagnosis and termination of pregnancy as an option for avoiding FD.

Polar body-based preimplantation diagnosis for X-linked disorders.

Preimplantation diagnosis for X-linked disorders has been performed predominantly by gender determination, which, however, leads to the discarding of 50% unaffected male embryos. In an attempt to identify X-linked mutation-free embryos for transfer, the present authors introduced preimplantation genetic diagnosis (PGD), using a sequential first and second polar body analysis, as an alternative to gender determination. This method was offered to eight couples at risk for having children with X-linked disorders, including haemophilia B, fragile-X syndrome (FMR1), myotubular myotonic dystrophy (MTMD), ornithine transcarbamylase (OTC) deficiency and X-linked hydrocephalus. The first and second polar bodies were removed following maturation and fertilization of oocytes in a standard IVF protocol and analysed using a multiplex nested polymerase chain reaction (PCR), involving testing for mutations simultaneously with linked markers. Overall, 13 PGD cycles were performed, resulting in the detection of 25 embryos with the predicted mutation-free maternal contribution; these embryos were transferred back to the patients in all cycles, yielding four clinical pregnancies. Four children were born following these pregnancies, including three unaffected and one with misdiagnosis as a result of allele dropout (ADO), which was predictable in the case of FMR1. Presented results demonstrate the clinical usefulness of the specific polar body testing for X-linked disorders as an alternative to PGD by gender determination.

Preembryonic diagnosis for sickle cell disease.

Embryos found to be abnormal during preimplantation genetic diagnosis are discarded or analyzed to confirm the diagnosis. The destruction of affected embryos is ethically unacceptable to some couples. We developed a preembryonic genetic diagnosis, that uses sequential first and second polar body removal, followed by oocyte freezing at the pronuclear stage. This was applied in a patient at risk of having a child with sickle cell disease, who suffered hyper-stimulation syndrome. Fourteen oocytes were obtained and tested for the maternal sickle cell allele by PCR analysis of the first and second polar body. Immediately after procedure of polar body removal, the pronuclear-stage oocytes were frozen. Six mutation-free oocytes detected by polar body analysis were then thawed, allowed to cleave, and transferred in the two consecutive clinical cycles, both resulting in clinical pregnancies, one of which resulted in birth of a healthy child. The oocytes predicted to contain abnormal beta-globin gene were not further cultured, to avoid formation and discard of the affected embryos. The results demonstrate feasibility of preembryonic diagnosis for single gene disorders, avoiding the establishment and destruction of mutant embryos.

Reliability of preimplantation diagnosis for single gene disorders.

Reliability of preimplantation genetic diagnosis (PGD) depends on controlling one of the most important limitations of single cell PCR, undetected allele drop out (ADO), which may lead to misdiagnosis. To avoid this we introduced mutation analysis simultaneously with linked polymorphic markers, pre-selecting only those embryos whose unaffected status could be confirmed by at least one linked polymorphic marker. We applied this strategy for testing 1047 oocytes, from which 237 unaffected ones were pre-selected for transfer back to patients, resulting in 34 unaffected pregnancies and birth of 23 healthy children. Embryos originating from mutant oocytes and those with insufficient marker information were followed up by multiplex PCR to confirm single cell PCR diagnosis. Of 75 (8.5%) detected ADO, only seven (under 1%) were missed in the actual PGD, demonstrating high reliability of PGD (98%) based on multiplex single cell PCR.

Preimplantation testing for phenylketonuria.

OBJECTIVE: To use preimplantation genetic diagnosis to achieve a phenylketonuria-free pregnancy in a couple at 50% risk for producing an affected child. DESIGN: DNA analysis of the first and second polar bodies (PB1 and PB2) obtained from oocytes of a heterozygous mother in IVF-ET, with the goal of identifying and transferring back to the patient the embryos resulting from mutation-free oocytes. SETTING: IVF program of Reproductive Genetics Institute, Chicago, Illinois. PATIENT(S): A mother carrying the R408W mutation and a father with compound heterozygosity for R408 and Y414C mutations in phenylalanine hydroxylase (PAH) gene. INTERVENTION(S): Removal and testing for maternal mutation in PB1 and PB2 from each oocyte after standard IVF. MAIN OUTCOME MEASURE(S): DNA analysis of PB1 and PB2 indicating whether corresponding oocytes were mutation-free, for the purposes of transferring only unaffected embryos resulting from these oocytes. RESULT(S): Of 11 zygotes with both PB1 and PB2, 6 were predicted to be free of phenylketonuria. Of these, 4 were transferred, resulting in an unaffected twin pregnancy and birth of two healthy children. CONCLUSION(S): Preimplantation genetic diagnosis of phenylketonuria resulted in the birth of phenylketonuria-free children. Preimplantation genetic diagnosis by PB analysis in couples with a compound heterozygous male partner is clinically useful.

Preimplantation diagnosis for ornithine transcarbamylase deficiency.

Ornithine transcarbamylase (OTC) deficiency is a severe X-linked metabolic disorder leading to hyperammonaemia and death shortly after birth. Prenatal diagnosis for OTC deficiency is available, but may require termination of pregnancy if affected. Thus there is a need for an option for pre-pregnancy testing, to pre-select OTC deficiency-free embryos for transfer, thus avoiding prenatal diagnosis and pregnancy termination. Preimplantation genetic diagnosis (PGD) for OTC deficiency has been developed, using sequential first and second polar body analysis; it was applied in a woman carrying the R26Q mutation in the exon 1 of OTC gene. The first and second polar bodies were removed following maturation and fertilization of oocytes in a standard IVF protocol, and analysed using a multiplex nested PCR. R26Q mutation was tested simultaneously with linked markers in six zygotes, resulting in detection of the embryos with a mutation-free maternal contribution; these were transferred back to the patient, yielding pregnancy and birth of a healthy child. This is the first PGD for OTC deficiency resulting in the birth of an unaffected child.

Prepregnancy testing for single-gene disorders by polar body analysis.

Preventive measures for single-gene disorders are currently based on carrier screening in pregnancy and prenatal diagnosis. Although this has been extremely effective for preventing new cases of common inherited conditions, the major limitation is still termination of 25% of wanted pregnancies following detection of affected fetuses. To overcome this important problem, we developed a method for prepregnancy genetic testing that involves DNA analysis of the first and second polar bodies, which are extruded during maturation and fertilization of oocytes. We offered this option to 28 couples at risk for having children with single-gene disorders. Fifty clinical cycles were performed from these patients for the following conditions: 20 for cystic fibrosis, 18 for thalassemia, 6 for sickle cell disease, 2 each for Gaucher disease and LCHAD (long-chain 3-hydroxyacyl-COA dehydrogenase deficiency), and 1 each for hemophilia B and phenylketonuria. Oocytes obtained from these patients using in vitro fertilization procedures (IVF) were tested by a sequential multiplex nested PCR analysis of the first and second polar body to detect the gene involved simultaneously with linked polymorphic markers. A total of 191 of 399 oocytes with predicted genotype were mutation free and preselected for fertilization and transfer. In all but three cycles, one to three unaffected embryos with predicted unaffected genotypes were transferred, resulting in 20 pregnancies, from which 19 healthy children have been born. The follow-up analysis of embryos resulting from oocytes with predicted affected genotype, confirmed the diagnosis in 97% of cases, demonstrating the reliability of prepregnancy diagnosis of single-gene defects by polar body analysis.

Accuracy of preimplantation diagnosis of single-gene disorders by polar body analysis of oocytes.

PURPOSE: A number of pitfalls in single-cell DNA analysis, including undetected DNA contamination, undetected allele drop out, and preferential amplification, may lead to misdiagnosis in preimplantation genetic diagnosis of single-gene disorders. METHODS: Preimplantation genetic diagnosis was performed by sequential first and second polar body analysis of oocytes in 26 couples at risk for having children with various single-gene disorders. Mutant genes were amplified simultaneously with linked polymorphic markers, and only embryos resulting from the mutation-free oocytes predicted by polar body analysis with confirmation by polymorphic marker testing were transferred back to patients. RESULTS: Overall 529 oocytes from 48 clinical cycles (26 patients) were tested, resulting in the transfer of 106 embryos in 44 clinical cycles. As many as 46 (9.6%) instances of allele dropout were observed, the majority (96%) of which were detected. Seventeen unaffected pregnancies were established, of which nine resulted in the birth of an unaffected child, and the rest are ongoing. CONCLUSIONS: A high accuracy of preimplantation genetic diagnosis of single-gene disorders is achieved by application of sequential analysis of the first and second polar body and multiplex polymerase chain reaction.

Birth of healthy children after preimplantation diagnosis of thalassemias.

BACKGROUND: Preimplantation genetic diagnosis (PGD) allows couples at risk of having children with thalassemia to ensure the healthy outcome of their pregnancy. METHODS: Seventeen PGD clinical cycles were initiated for Cypriot couples at risk of having children with different thalassemia mutations, including IVSI-110, IVSI-6, and IVS II-745. Unaffected embryos for transfer were selected by testing oocytes, using first and second polar body (PB) removal and nested polymerase chain reaction analysis followed by restriction digestion. RESULTS: Unaffected embryos were selected in 16 of 17 PGD cycles. Of 166 oocytes studied from these cycles, 110 were analyzed by sequential analysis of both the first and the second PB, resulting in preselection and transfer of 45 unaffected embryos. This resulted in seven pregnancies and in the birth of five healthy thalassemia-free children. The embryos predicted to have inherited the affected allele were not transferred. Analysis of these embryos confirmed the PB diagnosis. CONCLUSIONS: Sequential first and second PB testing of oocytes is reliable for PGD of thalassemia and is a feasible alternative to prenatal diagnosis in high-risk populations.

Construction and sequence analysis of subtraction complementary DNA libraries from human preimplantation embryos.

PURPOSE: Because stage-specific genetic expression in human preimplantation development is not sufficiently studied, we have undertaken the construction of a subtraction complementary DNA (cDNA) library enriched for transcripts specific for human blastocysts. METHODS: For this purpose individual pools of cDNAs synthesized from four hatched blastocysts and three cleaving 8- to 10-cell embryos were exposed to suppression subtractive hybridization to minimize the presence of transcripts of housekeeping genes and other genes of maternal origin known to be expressed earlier in preimplantation development. Random clones of this library were sequenced and analyzed using the BLAST algorithm. RESULTS: The resulting subtraction library had a complexity of 3 x 10(5) and an average size of inserts of about 0.8 kb. Sequencing of random library clones revealed the following human genes: CD9 antigen, fatty acid binding protein, ferritin heavy chain, amyloid precursor, MAP kinase messenger RNAs, DNA clone 127H14, messenger RNA for diacylglycerol kinase, a sequence homologous to C1 inhibitor, messenger RNA for the KIAA0145 gene, and others. CONCLUSIONS: The presence of these genes in human preimplantation development suggests expression specific to the blastocyst stage.

Preimplantation diagnosis of single disorders.

Preimplantation diagnosis of inherited and chromosomal diseases provides an option for couples at risk for conceiving genetically abnormal fetus to avoid a birth of an affected child without the need for a prenatal diagnosis and selective abortion of affected fetus (1-3). In some countries this might be the only way to the prevention of genetic disease, as abortion is not acceptable procedure. Even in those countries where prenatal diagnosis is practiced for many years, there is also concern that existing genetic programs based on prenatal screening will lead to increasing number of abortions. On the other hand, the possibilities for genotyping oocytes and cleaving embryos open a new prospect for genetic diagnosis before pregnancy, making genetic programs more ethically acceptable in any social setting. This will make preimplantation diagnosis the method of choice in the community based programs for prevention of genetic disease in the future, as well as a useful addition to assisted reproduction technologies, at least for IVF patients of advanced maternal age.

Isolation of cDNA libraries from individual human preimplantation embryos.

Although available data from the mouse model suggest that morphogenesis during preimplantation development is dependent on the expression of embryonic genes, convincing data for human preimplantation embryos are missing. To investigate the expression of genes involved in human preimplantation development we constructed cDNA libraries from human individual blastocysts and screened them for the expression of beta-actin, CD59, homeoboxes OCT-3 and HOXA4, and HLA-G and hMLH-1 genes. Beta-actin, CD59, and OCT-3 were detected by reverse transcription-polymerase chain reaction (RT-PCR), while HOXA4, HLA-G and hMLH-1 were undetected. Sequencing of 48 random clones from two libraries revealed a different identity to the known genes including 99% identity to human histone 3.1 and human ribosome protein S25 complete cDNA. These data demonstrate the feasibility of constructing cDNA libraries from individual human preimplantation embryos and their potential usefulness in the assessment of the relevance of specific gene expression in the failures of preimplantation development.

Preimplantation diagnosis of thalassemias.

PURPOSE: Preimplantation genetic diagnosis (PGD) is an important option for couples at risk of having children with beta-globin mutations to avoid selective abortions of affected fetuses following prenatal diagnosis. METHODS: We performed PGD for thalassemia in 12 clinical cycles (IVS1-110, and IVS-745 mutations) using biopsy of the first and second polar bodies (PBs) extruded from oocytes during maturation and fertilization, coupled with nested polymerase chain reaction analysis and restriction digestion. RESULTS: A total of 118 oocytes was obtained, of which 78 had results for both the first and the second PBs. This resulted in the selection and transfer of 30 unaffected embryos (2.5 embryos per cycle). To avoid a possible misdiagnosis due to allele dropout (ADO), we have also introduced simultaneous detection of two highly polymorphic linked markers, a short tandem repeat immediately at the 5' end of the globin gene and HUMTH01 which is a syntenic short tandem repeat. The application of multiplex polymerase chain reaction of the beta-globin gene and linked polymorphic markers enabled detection of ADO in five first PBs, thus avoiding the transfer of potentially affected embryos resulting from their corresponding oocytes. CONCLUSIONS: Confirmation studies of the embryos resulting from the oocytes predicted to contain an affected gene confirmed the diagnosis in 98% of the cases, thus demonstrating the accuracy and reliability of PB PGD of thalassemia mutations. The application of PB analysis in six patients resulted in two ongoing pregnancies with a thalassemia-free fetus already confirmed in both of them by prenatal diagnosis.

Allele dropout in polar bodies and blastomeres.

PURPOSE: Because allele dropout (ADO) is frequently observed in single-cell polymerase chain reaction analysis, it is important to develop a method for efficient detection of ADO, in order to avoid possible misdiagnosis in preimplantation diagnosis. METHODS: We introduced a simultaneous amplification of mutant genes and linked polymorphic markers, such as a 4-bp repeat (GATT) at the 3' end of intron 6 in the cystic fibrosis (CF) gene and a short tandem repeat at the 5' end of the beta-globin gene. Three types of single heterozygous cells were studied for the amplification of both alleles, including 150 blastomeres, 1615 fibroblasts, and 170 first polar bodies, obtained from patients at risk for having children with cystic fibrosis (delta F-508 mutation) or sickle cell disease. RESULTS: ADO rates of as high as 33.3% for delta F-508 mutation and 22.8% for beta-globin gene were observed in single blastomeres, compared to 7.1 and 7.7% in single fibroblasts and 5.9 and 9.6% in first polar bodies, respectively. The application of simultaneous amplification of the above linked polymorphic markers allowed detection of more than half of the cases of ADO in blastomeres (19.4% for cystic fibrosis and 12.3% for beta-globin gene) and almost all ADOs in polar bodies, particularly when the two-step sequential analysis of the first and second polar body was applied in preimplantation diagnosis of single gene disorders. CONCLUSIONS: Simultaneous amplification of linked polymorphic markers in single-cell DNA analysis of single-gene defects is an efficient method for avoiding the risk of misdiagnosis in preimplantation diagnosis.