Research progress on mosaic embryo transfer and pregnancy risk / 中华预防医学杂志

Mosaic embryos contain two or more genetically distinct cell lines, which can be detected by pre-implantation genetic testing for aneuploidy. At present, it has been reported that mosaic embryo transfer can lead to healthy live births. In order to prevent severe adverse pregnancy outcomes, such as implantation failure, abortion, congenital malformation and neonatal death after implantation of mosaic embryos, it is critical to carry out genetic counseling, prenatal diagnosis and pregnancy supervision for mosaic embryo transfer. This article reviews the selection of mosaic embryos, the pregnancy outcomes of mosaic embryo transfer, and the safety of offspring, in order to provide references for the clinical practice of mosaic embryo transfer.

Application of single sperm sequencing for the preimplantation genetic testing of a Chinese family affected with Spinal muscular atrophy / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of single sperm sequencing in preimplantation genetic testing for monogenic disease (PGT-M).@*METHODS@#A Chinese couple with two children whom had died of Spinal muscular atrophy (SMA) and attended the Jiangxi Provincial Maternal and Child Health Care Hospital in June 2020 was selected as the subject. Eleven single sperm samples were isolated by mechanical immobilization and subjected to whole genome amplification. Real-time PCR and Sanger sequencing were used to detect the SMN1 variants in the single sperm samples. Genomic DNA of the wife, her parents and the husband, as well as one single sperm sample harboring the SMN1 variant and two single sperm samples without the variant were used for the linkage analysis. Targeted capture and high-throughput sequencing were carried out to test 100 single nucleotide polymorphisms distributed within 2 Mb up- and downstream the variant site. The haplotypes linked with the SMN1 variants were determined by linkage analysis. Blastocyst embryos were harvested after fertilizing by intracytoplasmic sperm injection. Cells from the trophoblasts of each embryo were biopsied and subjected to whole genome amplification and targeted capture and high-throughput sequencing to determine their carrier status. Chromosomal aneuploidy of wild-type embryos was excluded. An euploid embryo of high quality was transferred. Amniotic fluid sample was taken at 18 weeks of gestation to confirm the status of the fetus.@*RESULTS@#Genetic testing showed that the couple both had deletion of exons 7 ~ 8 of the SMN1 gene. The wife has inherited the deletion from her father, while the husband was de novo. The haplotypes of the husband were successfully constructed by single sperm sequencing. Preimplantation genetic testing has indicated that 5 embryos had harbored the heterozygous variant, 4 embryos were of the wild type, among which 3 were euploid. Prenatal diagnosis during the second trimester of pregnancy has confirmed that the fetus did not carry the deletion.@*CONCLUSION@#By single sperm sequencing and PGT-M, the birth of further affected child has been successfully avoided.

Preimplantation genetic testing for monogenic/single gene disorders in a family with Molybdenum co-factor deficiency / 中华医学遗传学杂志

OBJECTIVE@#To carry out preimplantation genetic testing for monogenic/single gene disorders (PGT-M) for a Chinese family affected with Molybdenum co-factor deficiency due to pathogenic variant of MOCS2 gene.@*METHODS@#A family with molybdenum co-factor deficiency who attended to the Maternal and Child Health Care Hospital of Guangxi Zhuang Autonomous Region in April 2020 was selected as the research subject. Trophoblast cells were biopsied from blastocysts fertilized by intracytoplasmic sperm injection. Embryos carrying the MOCS2 gene variant and chromosome copy number variation (CNV) of more than 4 Mb were detected by single-cell whole genome amplification, high-throughput sequencing and single nucleotide polymorphism typing. Embryos without or carrying the heterozygous variant and without abnormal chromosome CNV were transplanted. During mid-pregnancy, amniotic fluid sample was collected for prenatal diagnosis to verify the results of PGT-M.@*RESULTS@#Eleven oocytes were obtained, among which three blastocysts were formed through culturing. Results of genetic testing suggested that one embryo was heterozygous for the maternally derived MOCS2 gene variant and without chromosomal CNV. Following embryo transfer, intrauterine singleton pregnancy was attained. Prenatal diagnosis by amniocentesis at 18 weeks of gestation revealed that the MOCS2 gene variant and chromosomal analysis results were both consistent with that of PGT-M, and a healthy male infant was born at 37+5 weeks of gestation.@*CONCLUSION@#PGT-M has helped the couple carrying the MOCS2 gene variant to have a healthy offspring, and may become an important method for couples carrying other pathogenic genetic variants.

Progress of research on chromosomal mosaicism embryos / 中华医学遗传学杂志

Chromosomal mosaicism (CM) is a common phenomenon in preimplantation genetic testing (PGT). In embryos with CM, genetic contents of trophoblastic ectodermal (TE) cells may be different from that of the inner cell mass (ICM) which will develop into the fetus. Embryos with low mosaic proportion could give rise to healthy live births after transplantation, but are accompanied with high pregnancy risks such as high abortion rate. In order to provide a more comprehensive understanding for CM embryos, this article has systematically summarized the recent progress of research on the definition, mechanism, classification, PGT techniques, self-correction mechanism, transplantation outcome and treatment principles for CM embryos.

Impact of inactivated SARS-CoV-2 vaccination on embryo ploidy: a retrospective cohort study of 133 PGT-A cycles in China

BACKGROUND: Unsubstantiated concerns have been raised on the potential correlation between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and infertility, leading to vaccine hesitancy in reproductive-aged population. Herein, we aim to evaluate the impact of inactivated SARS-CoV-2 vaccination on embryo ploidy, which is a critical indicator for embryo quality and pregnancy chance. METHODS: This was a retrospective cohort study of 133 patients who underwent preimplantation genetic testing for aneuploidy (PGT-A) cycles with next-generation sequencing technology from June 1st 2021 to March 17th 2022 at a tertiary-care medical center in China. Women fully vaccinated with two doses of Sinopharm or Sinovac inactivated vaccines (n = 66) were compared with unvaccinated women (n = 67). The primary outcome was the euploidy rate per cycle. Multivariate linear and logistic regression analyses were performed to adjust for potential confounders. RESULTS: The euploidy rate was similar between vaccinated and unvaccinated groups (23.2 ± 24.6% vs. 22.6 ± 25.9%, P = 0.768), with an adjusted ß of 0.01 (95% confidence interval [CI]: -0.08-0.10). After frozen-thawed single euploid blastocyst transfer, the two groups were also comparable in clinical pregnancy rate (75.0% vs. 60.0%, P = 0.289), with an adjusted odds ratio of 6.21 (95% CI: 0.76-50.88). No significant associations were observed between vaccination and cycle characteristics or other laboratory and pregnancy outcomes. CONCLUSIONS: Inactivated SARS-CoV-2 vaccination had no detrimental impact on embryo ploidy during in vitro fertilization treatment. Our finding provides further reassurance for vaccinated women who are planning to conceive. Future prospective cohort studies with larger datasets and longer follow-up are needed to confirm the conclusion.

Identification of pathogenic variant and preimplantation genetic testing for a Chinese family affected with osteogenesis imperfecta / 中华医学遗传学杂志

OBJECTIVE@#To identify the pathogenic variant for a husband with osteogenesis imperfecta and provide preimplantation genetic testing (PGT) for the couple.@*METHODS@#High-throughput sequencing and Sanger sequencing were carried out to identify the pathologic variant in the husband patients. PGT of embryos was performed through direct detection of the mutation site. Meanwhile, chromosome aneuploidy of the blastocysts was screened. Following transplantation, cytogenetic and genetic testing of fetal amniotic fluid sample was carried out during mid-pregnancy. Chromosome copy number variant (CNV) was detected at multiple sites of the placenta after delivery.@*RESULTS@#The husband was found to harbor heterozygous c.544-2A>G variant of the COL1A1 gene. The same variant was not detected in either of his parents. PGT revealed that out of three embryos of the couple, one was wild-type for the c.544-2A site but mosaicism for duplication of 16p13.3.11.2. The other two embryos were both heterozygous for the c.544-2A>G variant. Following adequate genetic counseling, the wild-type embryo was transplanted. Amniotic fluid testing confirmed that the fetus had normal chromosomes and did not carry the c.544-2A>G variant. The copy number of chromosomes at different parts of placenta was normal after birth.@*CONCLUSION@#For couples affected with monogenic disorders, e.g., osteogenesis imperfecta, direct detection of the mutation site may be used for PGT after identifying the pathogenic variant. After adequate genetic counseling, prenatal diagnosis must be carried out to ensure the result.

First Baby Born in Brazil after Simultaneous Diagnosis through Non-Invasive and Conventional PGT-A / Primeiro bebê nascido no Brasil após diagnóstico simultâneo por PGT-A não-invasivo e convencional

Abstract Non-invasive preimplantation genetic testing for aneuploidies (niPGT-A) aiming to assess cell-free embryonic DNA in spent culturemedia is promising, especially because it might overcome the diminished rates of implantation caused by the inadequate performance of trophectoderm (TE) biopsy. Our center is part of the largest study to date assessing the concordance between conventional PGT-A and niPGT-A, and we report here the delivery of the first baby born in Brazil using niPGT-A. The parents of the baby were admitted to our center in 2018. They did not present history of infertility, and they were interested in using in vitro fertilization (IVF) and PGT-A in order to avoid congenital anomalies in the offspring. A total of 11 (3 day-5 and 8 day-6) expanded blastocysts were biopsied, and the spent culture media (culture from day-4 to day-6) from 8 day-6 blastocysts were collected for niPGT-A. Overall, 7 embryos yielded informative results for trophectoderm (TE) and media samples. Among the embryos with informative results, 5 presented concordant diagnosis between conventional PGTA and niPGT-A, and 2 presented discordant diagnosis (1 false-positive and one falsenegative). The Blastocyst 4, diagnosed as 46, XY by both niPGT-A and conventional PGTA, was warmed up and transferred, resulting in the birth of a healthy 3.8 kg boy in February 2020. Based on our results and the recent literature, we believe that the safest current application of niPGT-A would be as a method of embryo selection for patients without an indication for conventional PGT-A. The approximate 80% of reliability of niPGT-A in the diagnosis of ploidy is superior to predictions provided by other noninvasive approaches like morphology and morphokinetics selection.

Resumo Abordagens para o teste genético pré-implantacional não-invasivo para aneuploidias (non-invasive preimplantation genetic testing for aneuploidies, niPGT-A, em inglês) com o objetivo de avaliar o DNA embrionário livre são promissoras, especialmente porque estas podem reverter as menores taxas de implantação causadas por inadequada biópsia de trofectoderma (TE). Nesse contexto, nosso centro é parte do maior estudo atual que avalia as taxas de concordância entre PGT-A convencional e niPGT-A, e relatamos aqui o nascimento do primeiro bebê brasileiro após niPGT-A. Os pais do bebê foram admitidos no nosso centro em 2018. Eles não apresentavam histórico de infertilidade, e estavam interessados em utilizar os tratamentos de fertilização in vitro (FIV) e PGT-A para evitar anomalias congênitas na progênie.Umtotal de 11 blastocistos expandidos (3 do dia-5 e 8 do dia-6) foram submetidos a biópsia, e os meios de cultivo condicionados (cultivo do dia-4 ao dia-6) de 8 blastocistos do dia-6 foram coletados para niPGT-A. No total, resultados informativos para as amostras de TE e dos meios foram obtidos para sete embriões. Entre os embriões com resultado informativo, 5 apresentaram diagnóstico concordante entre PGT-A convencional e niPGT-A, e 2 apresentaram diagnóstico discordante (1 falso positivo e 1 falso negativo). O Blastocisto 4, diagnosticado como 46, XY por ambos niPGT-A e PGT-A convencional, foi desvitrificado e transferido, o que resultou no nascimento de ummenino saudável, que pesava 3,8 kg, em fevereiro de 2020. Com base em nossos resultados e literatura contemporânea, acreditamos que a aplicação atualmais segura do niPGT-A seria como método de seleção embrionária para pacientes sem indicação ao PGT-A convencional. A confiabilidade aproximada de 80% do niPGT-A para determinação da ploidia ainda é superior àquela obtida com abordagens não invasivas, como seleção morfológica ou morfocinética.

Preimplantation Genetic Diagnosis of α/β Complex Thalassemia by Next Generation Sequencing / 中国实验血液学杂志

OBJECTIVE@#To explore the application value of next generation sequencing (NGS) in preimplantation genetic diagnosis of α/β complex thalassemia couple.@*METHODS@#The coding regions of α-globin genes (HBA1, HBA2) and β-globin gene (HBB) were selected as the target regions. The high-density and closely linked single nucleotide polymorphism (SNP) sites were selected as the genetic linkage markers in the upstream and downstream 2M regions of the gene. After NGS, the effective SNP sites were selected to construct the haplotype of the couple, and the risk chromosome of the mutation carried by the couple was determined. The NGS technology was used to sequence the variations of HBA1, HBA2 and HBB directly and construct haplotype linkage analysis for preimplantation genetic diagnosis.@*RESULTS@#Direct sequencing and haplotype linkage analysis of HBA1, HBA2 and HBB showed that two of the six blastocysts were α/β complex thalassemia, one was β-thalassemia heterozygote, two were α-thalassemias heterozygotes, and one was intermediate α-thalassemia. A well-developed embryo underwent preimplantation genetic diagnosis was implanted into the mother's uterus, and a healthy infant was born at term.@*CONCLUSION@#Preimplantation genetic diagnosis can be carried out by NGS technology in α/β complex thalassemia couples, and abortion caused by aneuploid embryo selection can be avoided.

Preimplantation genetic testing for a couple where the husband is affected by osteogenesis imperfecta combined with balanced translocation using karyomapping technique / 中华医学遗传学杂志

OBJECTIVE@#To carry out preimplantation genetic testing (PGT) for a couple where the husband was affected by osteogenesis imperfecta combined with balanced translocation using the karyomapping technique.@*METHODS@#Blastocysts were detected using karyomapping, the carrier status of COL1A1 c.760G>A (p.Gly254Arg) variant and the carrier status of the translocated chromosome were analyzed simultaneously.@*RESULTS@#For a total of 10 blastocysts, two euploid blastocysts were found to not carry the COL1A1 c.760G>A (p.Gly254Arg) variant but a balanced translocation. After transplanting one of the blastocysts, clinical pregnancy was achieved. Amniocentesis at 18th gestational week and prenatal genetic testing was in keeping with the result of PGT.A healthy female was born at 40+4 weeks gestation.@*CONCLUSION@#For patients simultaneously carrying genetic variant and balanced chromosomal translocation, PGT can be performed with efficiency by the use of karyomapping method.

Application of mapping allele with resolved carrier status technique for preimplantation genetic testing in carriers with balanced chromosomal translocations / 中华医学遗传学杂志

OBJECTIVE@#To assess the application value of mapping allele with resolved carrier status (MaReCs) technique for preimplantation genetic testing (PGT).@*METHODS@#The characteristics of MaReCs for PGT and outcome of patients were retrospectively analyzed.@*RESULTS@#Compared with those who could not use the technique, carriers who have used the MaReCs technique were younger, had significantly higher level of anti-Mullerian hormone, more antral follicles, occytes, mature occytes, biopsied embryos and euploid embryos, and lower risks for de novo chromosomal abnormality (P 0.05). Carriers undergoing MaReCs test could preferentially select embryos with normal chromosome structures for the transfer.@*CONCLUSION@#Application of MaReCs has a prerequisite for having a minimum number of occytes and biopsied embryos and using discarded embryos sometimes. MaReCs is efficient for the detection of carrier status of embryos and attaining higher rate of pregnancy and live birth, which can significantly improve the outcome for couples carrying chromosomal translocations.

Birth of healthy neonate following preimplantation genetic diagnosis in a mother with mosaic Turner syndrome. Case report and review of the literature / Recién nacido sano después de diagnóstico genético preimplantatorio en una madre con síndrome de turner mosaico. reporte de caso y revisión de la literatura

RESUMEN Objetivos: reportar el caso de una paciente con síndrome de Turner en mosaico, a quien se le realizó un tratamiento de reproducción asistida con análisis genético preimplantatorio para aneuploidias, logrando el nacimiento de una niña sana con cariotipo normal, y realizar una revisión de la literatura sobre la utilidad del diagnóstico genético preimplantatorio en las mujeres con síndrome de Turner. Materiales y métodos: se presenta el caso de una mujer de 27 años, con diagnóstico de síndrome de Turner en mosaico y con alteración secundaria en la reserva ovárica, atendida en centro de referencia para el manejo de infertilidad en Medellín, Colombia, a quien se le realizó un tratamiento de fertilización in vitro con análisis genético preimplan-tatorio para prevenir la transmisión del síndrome de Turner a su descendencia. Se realizó una búsqueda de la literatura en las bases de datos Medline vía PubMed, Clinical Key, OVID, Embase, Lilacs, SciE- LO y Oxford Journals, con los siguientes términos: "Turner Syndrome", "Mosaic Turner", "Preim- plantation Genetic Screening", "Preimplantation Genetic Testing", "Preimplantation Genetic Diagnosis", "Pregnancy", "Successful pregnancy". Como criterios de inclusión se consideraron artículos tipo series y reportes de casos, cohortes y artículos de revisión desde enero de 1980 hasta junio de 2017, que incluyeran mujeres con síndrome de Turner embarazadas por medio de técnicas de fertilización in vitro, con sus propios óvulos, y que hubiesen sido sometidas a biopsia embrionaria para diagnóstico genético preimplantatorio. La búsqueda se limitó a los idiomas español e inglés. Resultados: un estudio cumplió con los criterios de inclusión. Tanto en este reporte como en nuestro caso, las pacientes con síndrome de Turner en mosaico se sometieron a varios ciclos de inyección intracitoplasmática de espermatozoides (ICSI) con sus propios óvulos, luego se realizó biopsia em- brionaria para análisis genético preimplantatorio utilizando diferentes técnicas. En ambos casos se logró la transferencia al útero de embriones euploides con el posterior nacimiento de niñas sanas con cariotipo normal. Conclusión: Las pacientes con ST mosaico podrían beneficiarse de la biopsia embrionaria y análisis genético preimplantatorio para prevenir la transmisión del defecto genético a su descendencia.

ABSTRACT Objectives: To report the case of a patient with mosaic Turner syndrome who underwent assisted reproduction treatment with preimplantation genetic testing for aneuploidy and gave birth to a healthy baby girl with normal karyotype; and to conduct a review of the literature on the usefulness of preimplantation genetic diagnosis in women with Turner syndrome. Materials and methods: A case of a 27 year-old woman diagnosed with mosaic Turner syndrome and secondary altered ovarian reserve, seen in a referral center for infertility management in Medellín, Colombia. The patient underwent in vitro fertilization followed by pre-implantation genetic testing to prevent transmission of Turner syndrome to her progeny. A literature search was conducted in the Medline via PubMed, Clinical Key, OVID, Embase, Lilacs, SciELO and Oxford Journals data- bases using the following terms: "Turner Syndrome," "Mosaic Turner," "Preimplantation Genetic Screening," "Preimplantation Genetic Testing," "Preimplantation Genetic Diagnosis," "Pregnancy," "Successful pregnancy." Inclusion criteria were case series and case reports, cohort studies and review articles published between January 1980 and June 2017 that included women with Turner syndrome achieving pregnancy by means of in vitro fertilization techniques with their own oocytes and who had undergone embryo biopsy for preimplantation genetic diagnosis. The search was limited to articles in Spanish and English. Results: one study met the inclusion criteria. Both in this report and in our case, patients with mosaic Turner syndrome underwent several cycles of intracytoplasmic sperm injection (ICSI) with their own eggs, then performed embryonic biopsy for preimplantation genetic analysis using different techniques. In both cases, euploid embryos were transferred to the uterus with the subsequent birth of healthy girls with normal karyotype. Conclusion: Patients with mosaic Turner syndrome could benefit from preimplantation biopsy and genetic analysis to prevent transmission of the genetic defect to their progeny.

Application of next generation sequencing for preimplantation genetic test of 71 couples with one partner carrying a reciprocal or Robertsonian translocation / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of preimplantation genetic test (PGT) based on next generation sequencing (NGS) for achieving pregnancy for 71 couples with one partner carrying a reciprocal or Robertsonian translocation.@*METHODS@#Following blastocyst biopsy, whole genome of single cell was amplified, and PGT was performed by NGS. The subjects included 60 couples with one partner carrying a reciprocal translocation and 11 with one partner carrying a Robertsonian translocation. The results of PGT, implantation and prenatal diagnosis for all of the couples were analyzed.@*RESULTS@#In total 301 embryos were obtained for the 71 couples through 92 ovulation cycles, 287 (95.3%) of which were successfully diagnosed by NGS. Eighty-five euploidy embryos were identified for the reciprocal translocation carrier group. In 18 cycles, no euploid embryo was obtained. Cancellation rate for the cycles was 19.5%. For reciprocal translocation carrier group and Robertsonian translocation carrier group, the rates for implantation, early abortion, and clinical pregnancy were 89.3% (42/47), 25.5% (12/47), 63.8% (30/47), and 88.8% (8/9), 22.2% (2/9), and 66.6% (6/9), respectively. The result of prenatal diagnosis was consistent with the that of PGT.@*CONCLUSION@#PGT based on NGS can effectively identify euploid embryos and reduce recurrent abortions and termination of pregnancies, achieving a satisfactory rate for clinical pregnancy.

Birth of a healthy baby after preimplantation genetic diagnosis in a carrier of mucopolysaccharidosis type II: The first case in Korea / 대한생식의학회지

Mucopolysaccharidosis type II (MPS II) is a rare X-linked recessive lysosomal storage disease caused by mutation of the iduronate-2-sulfatase gene. The mutation results in iduronate-2-sulfatase deficiency, which causes the progressive accumulation of heparan sulfate and dermatan sulfate in cellular lysosomes. The phenotype, age of onset, and symptoms of MPS II vary; accordingly, the disease can be classified into either the early-onset type or the late-onset type, depending on the age of onset and the severity of the symptoms. In patients with severe MPS II, symptoms typically first appear between 2 and 5 years of age. Patients with severe MPS II usually die in the second decade of life although some patients with less severe disease have survived into their fifth or sixth decade. Here, we report the establishment of a preimplantation genetic diagnosis (PGD) strategy using multiplex nested polymerase chain reaction, direct sequencing, and linkage analysis. Unaffected embryos were selected via the diagnosis of a single blastomere, and a healthy boy was delivered by a female carrier of MPS II. This is the first successful application of PGD in a patient with MPS II in Korea

Genetic Analysis, Prenatal Diagnosis and Preimplantation Genetic Diagnosis of Taiwanese Deletion β-Thalassemia / 中国实验血液学杂志

OBJECTIVE@#To perform genetic analysis, prenatal diagnosis and preimplantation genetic diagnosis (PGD) in a family with a rare deletional β- thalassemia.@*METHODS@#Hematological parameters of the peripheral blood collected from all the family members were analyzed by whole blood cell analysis and capillary zone electrophoresis (CZE). Polymerase chain reaction-reverse dot blot (PCR-RDB) was used to identify 17 common β- thalassemia gene mutations, the multiplex ligation-dependent probe amplification (MLPA) and gap-polymerase chain reaction (gap-PCR) were used to identify β- globin gene cluster deletions. Chorionic villus sample or umbilical cord blood was obtained for prenatal diagnosis. Oligo-cells from blastocyst biopsy were collected for preimplantation genetic diagnosis by whole genome amplification and next generation sequencing.@*RESULTS@#The proband was a carrier of Taiwanese deletion β- thalassemia, two fetuses were both thalassemia majors. The PGD results showed that 6 of 11 tested embryos could be choose for transplantation.@*CONCLUSION@#The Taiwanese deletion is a rare type deletion of β- globin gene cluster, and it can lead to thalassemia intermedia or thalassemia major when compounded with other β- globin gene mutation. PGD is another choice for thalassemia couples.

Application of NGS-based SNP haplotyping for preimplantation genetic diagnosis for beta-thalassemia and HLA matching / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of next-generation sequencing (NGS)-based single nucleotide polymorphism (SNP) haplotyping for preimplantation genetic diagnosis (PGD) for beta-thalassemia coupled with human leukocyte antigen (HLA) matching.@*METHODS@#Three couples were recruited. Couple 1 both carried a β (IVS-2-654) variation and had previously given birth to a son with β thalassemia major. Couple 2 respectively carried (cd41-42) and β (IVS-2-654) but had no history of pregnancy. Couple 3 respectively carried β (CD17) and β (IVS-2-654), and had a daughter carrying β (CD17).@*RESULTS@#For couple 1, NGS-SNP typing identified two embryos not only unaffected with thalassemia but also with matched HLA. One blastocyst was transferred and resulted in successful pregnancy. A healthy baby was born at 39th week of gestation. Its umbilical blood was used to treat the sick brother through hemopoietic stem cell transplantation. For couple 2, seven blastocysts were obtained. Second transplantation has resulted in successful pregnancy. Prenatal diagnosis was consistent with PGD. For couple 3, two blastocysts not only unaffected with thalassemia but also with no pathogenic copy number variations were obtained. Transfer of one blastocyte resulted in successful pregnancy, and prenatal diagnosis was consistent with PGD.@*CONCLUSION@#NGS-based SNP typing is an useful tool for selecting embryos unaffected with beta-thalassemia and matched HLA through PGD.

Born to donate: proposals for "savior sibling" regulation in Latin America / Niños creados para servir de donantes de órganos: propuestas para una regulación en América Latina

Abstract A Savior Sibling is a child who is born to provide an organ, bone marrow or cell transplant, to a sibling that is affected with a fatal disease. There are created with the in vitro fertilization and pre-implantation genetic diagnosis and, in the process, the ethical standards for organ donation of children become less demanding. Therefore, we propose that the authorization of the technique considers, unavoidably, the opinion of an impartial third party that can guarantee the welfare of the child. We develop a critical analysis of the laws that regulate the creation of babies to serve as organ donors. We evaluate under what circumstances the organizations that play a part in the decisions, fulfill the ethical standards to allow the organ donation of children.

Resumen Los llamados Savior Sibling son bebés creados con la técnica de la fertilización in vitro y el diagnóstico preimplantacional genético, con el fin de servir como donantes a un hermano afectado por una enfermedad fatal. Se crean con el diagnóstico genético de fertilización in vitro y preimplantación y, en el proceso, las normas éticas para la donación de órganos a niños son menos exigentes. Por esta razón, proponemos que la autorización para llevar a cabo esta técnica considere, como obligatorio, la opinión de un tercero que sea imparcial y que pueda garantizar el bienestar del niño. Se hizo un análisis crítico de las leyes que regulan la creación de estos bebés que sirven como donantes de órganos. Evaluamos bajo qué circunstancias, las organizaciones que participan en estas decisiones cumplen con los estándares éticos para permitir la donación de órganos a niños.

Ethical problems with the preimplantation genetic diagnosis of human embryos / Problemas éticos con el diagnóstico genético preimplantacional de embriones humanos / Problemas éticos com diagnóstico pré-implantacional de embriões humanos

Abstract: 14. The purpose of preimplantation genetic diagnosis by embryonary biopsy is to identify genetic alterations prior to the implantation of embryos produced by in vitro fertilization. The most important aim is the selection of genetically healthy embryos due to their genetic indemnity, but it can also be used to select the sex or, eventually, other detectable traits accrding to the wishes of the parents. This procedure has been the subject of scientific debates, in relation to the harm that it can cause to healthy embryos that are going to be implanted, and in relation to the interpretation of the genetic tests made. Ethical debates have also focused on the production of and respect for the life and the integrity of developing human beings. In this work, it is argued that most of the uses of PGD are morally reprehensible, because they are done with disregard to the dignity that should be granted to embryos as human persons.

Resumen: 18. El diagnóstico genético preimplantacional (DGP) mediante biopsia embrionaria tiene como objeto la detección de alteraciones genéticas previamente a la implantación de embriones producidos por fertilización in vitro (FIV). Su finalidad más significativa es la selección de embriones por su indemnidad genética. También se puede emplear para seleccionar el sexo o eventualmente otras características detectadas según el deseo de los padres. Este procedimiento ha sido objeto de debates en el ámbito científico, por el eventual daño que puede ocasionar la técnica en embriones sanos que serán implantados y por las interpretaciones de los exámenes genéticos realizados. También ha sido objeto de debates en el ámbito ético-antropológico, en cuanto a la producción y al respeto a la vida e integridad de los seres humanos en desarrollo. En este trabajo se argumenta que los usos que se hacen del DGP son, en su gran mayoría, moralmente reprochables, por hacerse con desprecio de la dignidad que debe darse al embrión como persona humana.

Resumo: 22. O Diagnóstico genético pré-implantacional (PGD) por meio de biópsia embrionária visa a identificação de alterações genéticas prévias à implantação de embriões produzidos por fertilização in vitro (FIV). Seu propósito mais significativo é a seleção de embriões por sua característica genética. Ele também pode ser usado para selecionar o sexo ou, eventualmente, outras características identificadas de acordo com os desejos dos pais. Este procedimento tem sido tema de debate em âmbito científico, por eventual dano que pode ocaciosionar a técnica em embriões saudáveis que serão implantados e pela interpretações dos exames genéricos realizados. Ele também tem sido objeto de debate na área ético-antropológica, no que concerne a produção e o respeito à vida e integridade do ser humano em desenvolvimento. Este artigo argumenta que os usos que são feitos do PGD são, em sua grande maioria, moralmente condenáveis, por ser instrumentalizado com desrespeito pela dignidade que deve ser dada ao embrião como uma pessoa humana.

Analysis of chromosomes of embryos derived from translocation carriers during preimplantation genetic diagnosis cycles / 中华医学遗传学杂志

OBJECTIVE@#To explore the effect of chromosomal translocations on the composition of embryonic chromosomes and its mechanism.@*METHODS@#For 52 couples with one partner carrying a chromosomal translocation, results of next generation sequencing of all embryos derived from 61 cycles were divided into different groups based on the type of translocations, gender of the carrier, and maternal age. Effect of parental chromosomal translocations on the composition of embryonic chromosomes of each group was analyzed.@*RESULTS@#A significant difference was found between carriers of reciprocal and Robertsonian translocations in terms of proportion of abnormal embryos and structurally normal chromosomes (63.3% vs. 27.5%, and 1.1% vs. 0.3%, respectively). Compared with male carriers, there was an increase in the rate of abnormalities for female carriers (67.2% vs. 58.3% for reciprocal translocations, and 45.5% vs. 13.8% for Robertsonian translocations). The risk for chromosomal abnormality also increased with the maternal age. No significant difference was found in the proportion of abnormal embryos between carriers divided by involvement of acrocentric chromosomes or terminal chromosomal breakpoints.@*CONCLUSION@#The types of parental translocation, gender of carrier, maternal age, and interchromosomal effect have certain effect on the composition of embryonic chromosomes.

Outcomes of Preimplantation Genetic Diagnosis Cycles by Fluorescent Hybridization of Infertile Males with Nonmosaic 47,XYY Syndrome / 中华医学杂志(英文版)

Background@#The 47,XYY syndrome could result in fertility problems. However, seldom studies reported comprehensive researches on the embryonic development and pregnancy outcomes of these patients. This study aimed to evaluate the clinical outcomes of nonmosaic 47,XYY patients performed with fluorescent in situ hybridization (FISH) and preimplantation genetic diagnosis (PGD) treatment.@*Methods@#This was a retrospective study. Between January 2012 and May 2017, 51 infertile males with nonmosaic 47,XYY syndrome underwent FISH-PGD were included in the study. According to sex chromosomal FISH results, embryos were classified as normal signal, no nuclei fixed, no signal in fixed nuclei, suspensive signal, and abnormal signal groups, respectively. The incidence of each group, the fixation rate, and hybridization rate were calculated. Embryonic development and pregnancy outcomes were also analyzed. The measurement data were analyzed with Student's t-test. The comparison of categorical data was analyzed with the Chi-square test and Fisher's exact test when expected cell count was 0.05), and were significantly lower than the normal signal group (66.4%, P < 0.001). The clinical pregnancy rates of fresh and frozen embryos transferred cycles were 70.6% and 85.7%, respectively.@*Conclusions@#Among embryos with a clear diagnosis of sex chromosome, about one-fifth showed abnormal signals. Embryos with two sex chromosomal signals are more likely to develop into good-quality ones. The application of the PGD by FISH may help to improve the clinical outcome s.