Preimplantation Genetic Diagnosis of X-linked Severe Combined Immunodeficiency / 中山大学学报(医学科学版)

[Objective]To establish a reliable and accurate preimplantation genetic diagnosis (PGD)method using multiple dis?placement amplification (MDA), which can be applied to the diagnosis of X-linked severe combined immunodeficiency disease (X-SCID).[Methods]Haplotype analysis for the X-SCID family was performedusing five short tandem repeats (STR) markers flanking the both sides of the interleukin-2 (IL-2) receptor gamma chain (IL2RG) gene. MDA technique was used for single-cell whole genomic amplification. The products were used as template in polymerase chain reaction (PCR) of informative STR markers found by linkage analysis for haplotype analysis as well as sequencing of the IL2RG gene exon 5.The amelogenin (AMEL) locus was used to do sex diag?nosis.[Results]Linked analysis revealed 3 STR markers were informative. The method was evaluated with 10 single lymphocytes and 10 single blastomeres. MDA was successful in all single cell. The detection efficiency of gene sequencing of pathogenic IL 2RG exon5 was 100%. The PCR efficiency of 3 STR informative markers and AMEL was 96.3%(77/80)and the average allele drop-out (ADO) rate was 11.5%(7/61). A cycle of PGD was performed on the family, and seven embryos were diagnosed, two of which were normal embry?os. Twin pregnancy occurred after transplantation which were given a healthy baby boy and a healthy baby girl.[Conclusion]In this study, multiple displacement amplification combined with specific amplification/sequencing of pathogenic gene and haplotype analysis in the single cell level of X-linked severe combined immunodeficiency disease were performed. The protocol can avoid misdiagnosis caused by contamination and ADO, and improve the diagnostic efficiency of PGD.

Diagnóstico genético preimplantacional: análisis de aneuploidías únicas / Preimplantational genetic diagnosis: single aneuploidies analysis

Introducción: De las causas más conocidas en cuanto a la falta del éxito en el embarazo con tratamientos de reproducción asistida son aquellas relacionadas a las aneuploidías cromosómicas presentes en los embriones. El diagnóstico genético preimplantacional (PGD) es una técnica empleada en reproducción asistida para detectar estas anomalías, seleccionando aquellos que sean cromosómicamente normales, para luego transferirlos al útero de la paciente. Los embriones con aneuploidías únicas podrían tener la capacidad de sobrevivir y lograr la implantación, y por lo tanto, sin diagnóstico previo, estas podrían pasar desapercibidas. Objetivos: Determinar la incidencia de aneuploidías únicas en embriones de buena calidad embrionaria en el día 3 de desarrollo hasta blastocisto. Diseño: Estadístico y experimental. Instituciones: Reprogenetics Latinoamérica y Centro de Reproducción asistida, de la Clínica Concebir. Material Biológico: Muestras de biopsia embrionaria. Metodología: Análisis comparativo de resultados a partir de la evaluación de cada muestra obtenida por biopsia en el día tercero y día quinto de desarrollo embrionario, realizando el PGD por hibridación in situ (FISH) y genómica comparada (aCGH), respectivamente. Resultados: El 62,9% de embriones que presentaron monosomías únicas al tercer día de desarrollo embrionario resultaron ser de 8 células. Pero cuando se evaluó por aCGH en día cinco, 42,3% resultó anormal, y de estos 37,5% perteneció al estadio de 8 células. El índice de monosomías únicas en blastocisto resultó ser 57,9% de un total de 84,2% de aneuploidías únicas. Conclusiones: Los embriones de 8 células en el tercer día de desarrollo embrionario son los más probables de llegar al estadio de blastocisto, así como presentar aneuploidías únicas.

Background: Known causes of unsuccessful pregnancy in couples undergoing assisted reproduction treatment include embryo aneuploidies. Preimplantation genetic diagnosis (PGD) is a technique used in assisted reproduction in order to detect these abnormalities, select embryos chromosomally normal and subsequently transfer to the patients’ uterus. Embryos with single aneuploidies may have the ability to survive and achieve unnoticed implantation. Objectives: To determine incidence of single aneuploidies in good quality embryos in third day of development to blastocyst. Design: Statistical and experimental study. Setting: Reprogenetics Latin-America and Assisted Reproduction Center - Concebir. Biologic material: Samples of embryo biopsies. Methods: Comparative analysis of results from evaluation of each sample obtained by embryo biopsy on the third and fifth days of embryonic development, performing PGD by respectively in situ hybridization (FISH) and comparative genomics (aCGH). Results: On third day of embryonic development 62.9% of embryos with single monosomy had 8-cell morphology. Though when evaluated by aCGH in the blastocyst stage 42.3% were abnormal and 37.5% of these belonged to the 8-cell stage. Single monosomies index in the blastocyst stage was 57.9% in 84.2% of single aneuploidies. Conclusions: Eight-cell embryos on the third day of embryonic development are most likely to reach blastocyst stage and have single aneuploidies.

A Study of Guidelines for Genetic Counseling in Preimplantation Genetic Diagnosis (PGD)

PURPOSE: Preimplantation genetic diagnosis (PGD), also known as embryo screening, is a pre-pregnancy technique used to identify genetic defects in embryos created through in vitro fertilization. PGD is considered a means of prenatal diagnosis of genetic abnormalities. PGD is used when one or both genetic parents has a known genetic abnormality; testing is performed on an embryo to determine if it also carries the genetic abnormality. The main advantage of PGD is the avoidance of selective pregnancy termination as it imparts a high likelihood that the baby will be free of the disease under consideration. The application of PGD to genetic practices, reproductive medicine, and genetic counseling is becoming the key component of fertility practice because of the need to develop a custom PGD design for each couple. MATERIALS AND METHODS: In this study, a survey on the contents of genetic counseling in PGD was carried out via direct contact or e-mail with the patients and specialists who had experienced PGD during the three months from February to April 2010. RESULTS: A total of 91 persons including 60 patients, 49 of whom had a chromosomal disorder and 11 of whom had a single gene disorder, and 31 PGD specialists responded to the survey. Analysis of the survey results revealed that all respondents were well aware of the importance of genetic counseling in all steps of PGD including planning, operation, and follow-up. The patient group responded that the possibility of unexpected results (51.7%), genetic risk assessment and recurrence risk (46.7%), the reproduction options (46.7%), the procedure and limitation of PGD (43.3%) and the information of PGD technology (35.0%) should be included as a genetic counseling information. In detail, 51.7% of patients wanted to be counseled for the possibility of unexpected results and the recurrence risk, while 46.7% wanted to know their reproduction options (46.7%). Approximately 96.7% of specialists replied that a non-M.D. genetic counselor is necessary for effective and systematic genetic counseling in PGD because it is difficult for physicians to offer satisfying information to patients due to lack of counseling time and specific knowledge of the disorders. CONCLUSIONS: The information from the survey provides important insight into the overall present situation of genetic counseling for PGD in Korea. The survey results demonstrated that there is a general awareness that genetic counseling is essential for PGD, suggesting that appropriate genetic counseling may play a important role in the success of PGD. The establishment of genetic counseling guidelines for PGD may contribute to better planning and management strategies for PGD.

Preimplantation Genetic Diagnosis for Single Gene Disorders

Preimplantation genetic diagnosis (PGD) has become an assisted reproductive technique for couples who are at risk that enables them to have unaffected baby without facing the risk of pregnancy termination after invasive prenatal diagnosis. The molecular biology and technology for single-cell genetics has reached an extremely high level of accuracy, and has enabled the possibility of performing multiple diagnoses on one cell using whole genome amplification. These technological advances have contributed to the avoidance of misdiagnosis in PGD for single gene disorders. Polymerase chain reaction (PCR)-based PGD will lead to a significant increase in the number of disorders diagnosed and will find more widespread use, benefiting many more couples who are at risk of transmitting an inherited disease to their baby. In this review, we will focus on the molecular biological techniques that are currently in use in the most advanced centers for PGD for single gene disorders, including biopsy procedure, multiplex PCR and post-PCR diagnostic methods, and multiple displacement amplification (MDA) and the problems in the single cell genetic analysis.

Preliminary data of preimplantation genetic diagnosis for aneuploidy screening using fluorescent in situ hybridization in Siriraj Hospital.

Objective: Preimplantation genetic diagnosis (PGD) is technique for detecting genetic diseases. Preimplantation genetic diagnosis for aneuploidy screening (PGD-AS) using fluorescent in situ hybridization (FISH) has been used worldwide including at Siriraj Hospital. The objective of this study was to comparethe pregnancy rate between a PGD-AS group with standard assisted reproductive techniques (ARTs) in Siriraj Hospital. Methods: Couples who requested PGD-AS underwent a standard ARTs process followed with blastomere biopsy for FISH analysis. The pregnancy rate was compared among the PGD-AS group and the control group. The control group was divided into 2 subgroups – all patients required ARTs subgroup and age ≥ 35 yrs. subgroup. Results: 6 stimulated cycles from 4 patients were performed in the PGD-AS group. The pregnancy rate per stimulated cycle in the PGD-AS group, control group and age ≥ 35 yrs group were 33.33%, 16.20% and 12.05% respectively. Moreover, the pregnancy rate per transferred cycles in the PGD-AS group, control group and age ≥ 35 yrs group were 40.00%, 21.02% and 13.17% respectively. Conclusion: PGD is an advanced method for detecting genetic defects. PGA-AS might increase the pregnancy rate.

Preimplantation Genetic Diagnosis for alpha thalassemia: experience in Siriraj Hospital.

Objective: Detection of fetal thalassemia using preimplantation genetic diagnosis (PGD) can make a diagnosis before pregnancy so termination of pregnancy in that patient is eliminated. The objective of this study was to develop a single gene polymerase chain reaction (PCR) protocol for PGD of alpha thalassemia in Siriraj Hospital. Methods: A couple with a history of repeated Bart’s hemoglobinopathy in fetus underwent an artificial reproductive technique (ART) process using a standard ovarian stimulation protocol with intracytoplasmic sperm injection (ICSI) to reduce sperm DNA contamination. On day 3 post fertilization, laser biopsy was performed on the cleavage stage embryos to obtain a blastomere for PCR analysis of alpha thalassemia 1 SEA type. Results: 11 embryos from a total of 15 oocytes were biopsied, 2 normal, 1 alpha thal 1 trait and 3 affected embryos were detected. No contamination and allele drop out were detected, but a high PCR failure rate of 5 from 11 total biopsied embryos. Conclusion: PGD for alpha thalassemia was first established in Siriraj Hospital, but the result had a high failure rate so then optimized laboratory techniques were required.

Preimplantation Genetic Diagnosis for Ornithine Transcarbamylase Deficiency by Simultaneous Analysis of Duplex-nested PCR and Fluorescence In Situ Hybridization: A Case Report

Ornithine transcarbamylase (OTC) deficiency is an X-linked co-dominant disorder. A couple, with a previous history of a neonatal death and a therapeutical termination due to OTC deficiency, was referred to our center for preimplantation genetic diagnosis (PGD). The female partner has a nonsense mutation in the exon 9 of the OTC gene (R320X). We carried out nested polymerase chain reaction (PCR) for R320X mutation and fluorescence in situ hybridization (FISH) for aneuploidy screening. Among a total of 11 embryos, two blastomeres per embryo from 9 embryos were biopsied and analyzed by duplex-nested PCR and FISH, and one blastomere per embryo from 2 embryos by only duplex-nested PCR. As a result of PCR and restriction fragment length polymorphism analysis, four embryos were diagnosed as unaffected embryos having the normal OTC gene. Among these embryos, only one embryo was confirmed as euploidy for chromosome X, Y and 18 by FISH analysis. A single normal embryo was transferred to the mother, yielding an unaffected pregnancy and birth of a healthy boy. Based on our results, PCR for mutation loci and FISH for aneuploidy screening with two blastomeres from an embryo could provide higher accuracy for the selection of genetically and chromosomally normal embryos in the PGD for single gene defects.

Efficacy of Duplex-nested PCR and Fluorescent PCR in the Preimplantation Genetic Diagnosis for Duchenne Muscular Dystrophy / 대한불임학회지

OBJECTIVE: Preimplantation genetic diagnosis (PGD) is reserved for couples with a risk of transmitting a serious and incurable disease, and hence avoids the undesirable therapeutic abortion. In this study, we evaluated the efficacy of PGD for Duchenne muscular dystrophy (DMD) cases by the fluorescent PCR with polymorphic linked markers and the conventional duplex-nested PCR methods. METHODS: Biopsy of one or two blastomeres was done from the embryos fertilized by ICSI on the third day after fertilization. We performed two cases of PGD-DMD by the duplex-nested PCR for the causative mutation loci and the SRY gene on Y chromosome. The triplex fluorescent PCR for the mutation loci, the SRY gene and the polymorphic microsatellite marker on X chromosome was applied for two cases of PGD-DMD. RESULTS: By the duplex-nested PCR, successful diagnosis rate was 95.5% (21/22), but we could not discriminate the female embryos whether normal or carrier in this X-linked recessive disease. However, the triplex fluorescent PCR method showed 100% (27/27) of successful diagnosis rate, and all female embryos (n=17) were distinguished normal (n=10) from carrier (n=7) embryos. Unaffected and normal embryos were transferred into mother's uterus after diagnosis. A healthy normal male was achieved after PGD with the duplex-nested PCR method and a twin, a male and a female, were delivered with triplex fluorescent PCR method. The normality of dystrophin gene was confirmed by amniocentesis and postnatal genetic analysis in all offsprings. CONCLUSION: The fluorescent PCR with polymorphic marker might be useful in improving the specificity and reliability of PGD for single gene disorders.

Improvement of Pregnancy Rate in Preimplantation Genetic Diagnosis with FISH Procedure by the Laboratory Optimization and Experiences / 대한불임학회지

OBJECTIVES: This study was performed to evaluate the laboratory system for successful PGD using fluorescence in situ hybridization (FISH) and the clinical outcome of PGD cycles in five years experiences. METHODS: A total of 181 PGD-FISH cycles of 106 couples were performed, and diagnosed chromosome normality in the preimplantation embryos. The laboratory and clinical data were classified by the following optimization steps, and statistically analyzed. Phase I: Blastomere biopsy with two kinds of pipettes, removal of cytoplasmic proteins without treatment of pepsin and culture of biopsied embryos with single medium; Phase II: Blatomere biopsy with single pipette, removal of cytoplasmic proteins with pepsin and culture of biopsied embryos with single medium; Phase III: Blastomere biopsy with single pipette, removal of cytoplasmic proteins with pepsin and culture of biopsied embryos with sequential media. RESULTS: A total of 3,209 oocytes were collected, and 83.8% (2,212/2,640) of fertilization rate was obtained by ICSI procedure. The successful blastomere biopsies were accomplished in 98.6% (2,043/2,071) of embryos, and the successful diagnosis rate of FISH was 94.7% (1,935/ 2,043) of blastomeres from overall data. Embryo transfers with normal embryos were conducted in 93.9% (170/181) of started cycles. There was no difference in the successful rate of biopsy and diagnosis among Phase I, II and III. However, the pregnancy rate per embryo transfer of Phase III (38.8%, 26/67) was significantly (p<0.05) higher than those of Phase I (13.9%, 5/36) and Phase II (14.9%, 10/67). CONCLUSIONS: The laboratory optimization and experience for the PGD with FISH procedure can increase the pregnancy rate to 38.8% in the human IVF-ET program. Our facility of PGD with FISH provides the great possibility to get a normal pregnancy for the concerned couples by chromosomal aberrations.

Successful Preimplantation Genetic Diagnosis for Ornithine Transcarbamylase Deficiency, Junctional Epidermolysis Bullosa and Lactic Acidosis Using Duplex Nested PCR: Delivery of Healthy Baby by Specific Preimplantation Genetic Diagnosis for Ornithine Tran / 대한산부인과학회잡지

OBJECTIVE: Preimplantation genetic diagnosis (PGD) is reserved for couples with a risk of transmitting a serious and incurable disease, and hence avoids the undesirable therapeutic abortion. Herein, we report the result of PGD to carriers at risk of transmitting ornithine transcarbamylase (OTC) deficiency, junctional epidermolysis bullosa (EB) and lactic acidosis (LA) due to defect of pyruvate dehydrogenase alpha1 gene, respectively. METHODS: The ovarian stimulation, oocyte retrieval and ICSI procedure were undergone by conventional protocols. PGD for single gene disorders was carried out after biopsy of one or two blastomeres from the embryos on the third day. We performed the duplex nested PCR of the simultaneous amplification for the causative mutation loci as well as the SRY gene on Y chromosome in case of OTC deficiency and LA. Two different mutation loci of ITGB4 gene in EB case were amplified by the same protocol. The PCR products were analyzed by agarose gel electrophoresis, restriction fragment length polymorphism analysis or direct DNA sequencing. RESULTS: A total of 26 embryos were analyzed by duplex nested PCR. One or two blastomeres were biopsied, and successful diagnosis rate of PGD with PCR was 92.3% (24/26). There was no contamination in all PCR samples of negative controls (n=67). Five embryos (19.2%) were diagnosed as normal embryos, which were transferred to the mothers' uterus in each cases. In OTC deficiency case, singleton pregnancy was established. At 17 weeks of gestation, genetic normality of OTC gene in fetus was confirmed by amniocentesis. A healthy baby was successfully delivered at 36 weeks of gestation in OTC deficiency case. Unfortunately, pregnancies were not achievement in cases of EB and LA. CONCLUSION: This is the first report in Korea that healthy baby was born after specific PGD for OTC deficiency. Our results demonstrate that duplex nested PCR for single cell is an efficient method in identifying the gender and single gene mutation or two different mutation loci, simultaneously. This PGD procedure could provide normal healthy baby to the couple with a high risk of transmitting genetic diseases.

Clinical application of preimplantation genetic diagnosis (PGD) using fluorescence in-situ hybridization to balanced reciprocal or Robertsonian translocation carriers in human IVF-ET program / 대한산부인과학회잡지

OBJECTIVE: This study was performed to evaluate the efficiency of preimplantation genetic diagnosis (PGD) using fluorescence in-situ hybridization (FISH) in Robertsonian or balanced reciprocal translocation carriers in human IVF-ET programm. METHOD: FISH was carried out in 25 cycles of 15 couples. Two-color FISH analysis was performed on 54 polar bodies in 3 cycles and 234 blastomeres in 22 cycles. After FISH analysis, the embryos with normal FISH signals were transferred into mother's uterus. RESULTS: In FISH analysis of polar bodies, 18 nuclei of polar bodies were normal and 12 embryos were transferred in 3 cycles. FISH efficiency per oocyte was 95.0% in cases using polar bodies. In FISH analysis of blastomeres, 49 embryos were normal and transferred in 21 cycles. FISH efficiency per embryo was 92.7% using blastomeres. At present, three pregnancies were achieved. A girl and a boy were delivered. Both of them were translocation carriers. The other conceptus showed normal karyotype. CONCLUSIONS: According to this study, PGD using FISH can be successfully applied for the patients with translocations of chromosomes.

Influential Factors And Strategies of Preimplantation Genetic Diagnosis Informed Consent / 中国医学伦理学

Preimplantation Genetic Diagnosis(PGD) is a pre-gestational diagnostic technique used to identify genetic defects in embryos created through in vitro fertilization prior to transfer into the uterus.It is currently the only option available to avoid the dilemma of a pregnancy termination due to unfavorable prenatal diagnosis of high risk genetic diseases,however,the limitation of this technique could result in uncertain results.To avoid ethics disputes,patients must undergo a medical informed consent process to fully understand the risks prior to undergoing PGD.This process is often hampered by the patients' restricted recognition ability.Here we discuss possible strategies to help patients completely comprehend the critical issues relating to PGD,including comprehensiveness of PGD related information,and all possible benefits and risks of currently available operational and detection techniques.Based on this, It is necessary to sign a detailed medical informed consent according to different inherited disease.