1/8. Multiplex PCR combining deltaF508 mutation and intragenic microsatellites of the CFTR gene for pre-implantation genetic diagnosis (PGD) of cystic fibrosis.One major limitation of pre-implantation genetic diagnosis (PGD) practice comes from the need to develop single cell PCR protocols. For a disease such as cystic fibrosis (CF), for which almost 1000 mutations have been identified, the development of a mutation based PGD protocol is impracticable. An elegant way to overcome this problem is to set up an indirect diagnosis using polymorphic markers allowing the identification of the pathogenic haplotype instead of the mutation. We present here a new PGD protocol for CF. Our strategy is based on a multiplex fluorescent PCR co-amplifying the DeltaF508 mutation and two CFTR intragenic polymorphic microsatellites (IVS8CA and IVS17bCA). Such an approach is justified since in 91% of the cases at least one partner of the couple carries the DeltaF508 mutation. The use of intragenic markers reduces the risk of misdiagnosis due to meiotic recombination. In 97% of the single lymphoblasts (151/155) tested a PCR signal was obtained. A complete haplotyping was achieved in 137/151 (91%) lymphoblasts and a 6% rate of allele drop out (ADO) was observed. Three cases were performed. Case one was at risk of transmitting mutations DeltaF508 and R1162X, case 2 DeltaF508 and R1066C and case 3 DeltaF508 and 1341 1A. Considering these three cases and the re-analysis of the affected embryos, we have analysed 62 blastomeres from which we had PCR signal for 58 (94%) and a complete haplotype for 49 (84%). With the degree of polymorphism of the markers used in this work (48 and 39%) and the fact that we co-amplified the F508 locus our test should be suitable for nearly 80% of the couples requesting PGD for CF. This fluorescent multiplex PCR indirect diagnosis provides also a safer test since it allows the confirmation of the diagnosis, the detection of contamination and could give an indication on the ploidy of the embryos tested.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
2/8. Birth of healthy female twins after preimplantation genetic diagnosis of cystic fibrosis combined with gender determination.Two healthy sisters with a familial history of mental retardation were referred to our centre for preimplantation genetic diagnosis (PGD). Their two brothers showed severe mental retardation. The molecular basis for their disorder could not be identified, but one of the sisters and the mother presented a highly skewed pattern of X-inactivation reinforcing the likelihood of an X-linked mode of inheritance. Both sisters requested PGD to avoid the abortion of potentially affected male fetuses. PGD for sex by fluorescent in-situ hybridization was carried out for the first sister and resulted in the birth of a female child. The second sister and her partner, whose niece had cystic fibrosis (CF), were tested for CF mutations, and were both found to be deltaF508 heterozygous. We developed an efficient single cell PCR protocol for the simultaneous amplification of the CF (deltadeltaF508) locus as well as the X-linked amelogenin gene and its highly homologous pseudogene on the y chromosome. Two PGD cycles were carried out to screen against male and deltaF508 homozygous deleted embryos. In each case several embryos could be selected for transfer and the second cycle resulted in a twin pregnancy followed by the birth of two healthy female infants.- - - - - - - - - - ranking = 211.71237610461keywords = preimplantation, embryo (Clic here for more details about this article) |
3/8. Birth of a normal girl after in vitro fertilization and preimplantation diagnostic testing for cystic fibrosis.BACKGROUND. cystic fibrosis is a common, severe autosomal recessive disease caused in a majority of cases by a three-nucleotide deletion (delta F508) in the cystic fibrosis transmembrane regulator gene. Current methods of prenatal diagnosis involve chorionic-villus sampling or amniocentesis. in vitro fertilization and diagnosis during embryonic development before implantation would allow only unaffected embryos to be selected for transfer to the uterus, thereby avoiding the need to terminate a pregnancy. methods. preimplantation diagnosis of cystic fibrosis was attempted in the cases of three couples, both members of which carried the delta F508 deletion. in vitro fertilization techniques were used to recover oocytes from each woman and fertilize them with her husband's sperm. Three days after insemination, embryos in the cleavage stage underwent biopsy and removal of one or two cells for dna amplification and analysis. RESULTS. Only two oocytes from one woman were fertilized normally; dna analysis of one of the embryos failed and cystic fibrosis was diagnosed in the other (i.e., it was homozygous for delta F508), so neither was transferred. The oocytes of each of the other two women produced noncarrier, carrier, and affected embryos. Both couples chose to have one noncarrier embryo and one carrier embryo transferred. One woman became pregnant and gave birth to a girl free of the deletion in both chromosomes. CONCLUSIONS. preimplantation diagnosis of the delta F508 deletion causing cystic fibrosis is possible through in vitro fertilization, biopsy of a cleavage-stage embryo, and amplification of dna from single embryonic cells. This approach should be equally applicable to other single-gene diseases in which the defect has been identified. Analysis of a series of pregnancies, however, will be required to assess the method adequately.- - - - - - - - - - ranking = 173.06990088369keywords = preimplantation, embryo (Clic here for more details about this article) |
4/8. Duplex, triplex and quadruplex PCR for the preimplantation genetic diagnosis (PGD) of cystic fibrosis (CF), an exhaustive approach.Most of cystic fibrosis (CF) pre-implantation genetic diagnosis (PGD) cases described to date are limited to the detection of DeltaF508. Beside this predominant mutation, over 1000 mutations have been identified, rendering the development of a mutation-based PGD protocol impracticable. This is the reason why we, as well as the others, have developed PGD strategies on the basis of the identification of the pathogenic haplotype instead of the mutation(s). In a previous article, we reported the conditions for the co-amplification of two intragenic polymorphic markers and the F508 locus. Here we describe an improved protocol allowing the additional amplification of two new intragenic markers, intron 1 CA repeat (I1CA) and IVS17bTA. This new protocol should, theoretically, allow us to provide a diagnosis to all couples requiring PGD for CF. Using single lymphoblasts, we have tested four different PCR configurations, including one duplex, two triplexes and one quadruplex PCR. All of them gave results compatible with a clinical application. The number of single lymphoblasts tested in each series varied from 89 to 155. PCR efficiency ranged from 95.4 to 100%. A complete haplotype was achieved for 83.2 to 90.7% of the tested cells, with an allele drop out (ADO) rate comprised between 6.0 and 11.6%. We present here three cases that we performed either with the former test (one case using the triplex PCR combining F508, IVS8CA and IVS17bCA) or with the new one (one case using the triplex combining F508, I1CA and IVS17bTA and one case using a quadruplex test). We obtained two single pregnancies.- - - - - - - - - - ranking = 168.56990088369keywords = preimplantation (Clic here for more details about this article) |
5/8. Microscopic epididymal sperm aspiration (MESA): a new option for treatment of the obstructive azoospermia associated with cystic fibrosis.cystic fibrosis is a life-threatening disease. Only recently has the prognosis improved. In the male patient there is an almost invariable absence or maldevelopment of the vas deferens, creating a situation of obstructive azoospermia. Consequently, their fertility potential has been considered nonexistent. Having gained experience in microscopic epididymal sperm aspiration coupled with the advanced reproductive technologies for the treatment of congenital absence of the vasa, we sought to extend this treatment option to the male cystic fibrosis population. An Indian male with clinically evident and genetically confirmed cystic fibrosis underwent microscopic retrieval of epididymal sperm. The anatomy of the epididymis and the quality of sperm obtained were similar to those patients with congenital absence of the vas deferens. After appropriate spousal genetic testing, superovulation, and transvaginal oocyte retrieval, in vitro insemination of sperm was performed. Fifty percent of the oocytes were subjected to partial zona dissection and a single embryo resulted. Subsequent to transfer, no conception was realized but the effort expanded the clinical usefulness of microscopic epididymal sperm aspiration. This should open up an avenue of treatment for couples in whom only the most dire predictions for fertility have been made to date.- - - - - - - - - - ranking = 0.5keywords = embryo (Clic here for more details about this article) |
6/8. Proof of principle and first cases using preimplantation genetic haplotyping--a paradigm shift for embryo diagnosis.Preimplantation genetic haplotyping (PGH) proof-of-principle was demonstrated by multiple displacement amplification (MDA) of single buccal cells from a female donor and genotyping using 12 polymorphic markers within the dystrophin gene; the known paternal genotype enabled identification of the paternal haplotype in the MDA products despite 27% allele dropout. MDA amplified dna from 49 single human blastomeres with 100% success. The MDA products were genotyped using a total of 57 polymorphic markers for chromosomes 1, 7, 13, 18, 21, X and Y; 72% of alleles amplified providing results at 90% of the loci tested. A PGH cycle was carried out for Duchenne muscular dystrophy. One embryo was biopsied: PGH showed a non-carrier female, which was transferred with no resulting pregnancy. A PGH cycle was carried out for cystic fibrosis. Seven embryos were biopsied and PGH allowed the exclusion of 2 affected embryos; a carrier and a non-carrier embryo were transferred resulting in an on-going twin pregnancy. PGH represents a paradigm shift in embryo diagnosis, as one panel of markers can be used for all carriers of the same monogenic disease, bypassing the need for development of mutation-specific tests, and widening the scope and availability of preimplantation genetic testing.- - - - - - - - - - ranking = 215.21237610461keywords = preimplantation, embryo (Clic here for more details about this article) |
7/8. Birth after preimplantation diagnosis of the cystic fibrosis delta F508 mutation by polymerase chain reaction in human embryos resulting from intracytoplasmic sperm injection with epididymal sperm.Men with congenital bilateral absence of the vas deferens (CBAVD) have been regarded as presenting a mild form of cystic fibrosis (CF). In this article, we report a case of male-factor infertility, in which both partners are carriers of the delta F508 mutation and the male partner has CBAVD. Microsurgical epididymal sperm aspiration (MESA) was performed to obtain spermatozoa; intracytoplasmic sperm injection (ICSI) was carried out on the oocytes since the motility of the spermatozoa was severely impaired; and embryo biopsy and a polymerase chain reaction (PCR) were carried out for preimplantation diagnosis of the CF delta F508 mutation. Single-blastomere analysis was performed and indicated that two embryos were affected (homozygous delta F508) and three embryos were carriers. After transfer of the latter three embryos, a singleton pregnancy was established. At amniocentesis, the delta F508 carrier status of the fetus with a 46, XY karyotype was confirmed. A healthy boy was born and the presence of vasa deferentia, bilaterally, was confirmed. The CF sweat test was also normal. Successful fertilization can be obtained by combination of MESA and ICSI in patients with CBAVD. preimplantation diagnosis of CF is indicated. pregnancy and birth of normal children can ensue in such patients.- - - - - - - - - - ranking = 214.71237610461keywords = preimplantation, embryo (Clic here for more details about this article) |
8/8. Case report: cystic fibrosis and embryonal carcinoma of the testis.The authors describe a patient with cystic fibrosis and a stage III testicular embryonal cell cancer. Because cystic fibrosis occurs in approximately 1 of 2,500 births and embryonal carcinoma in 3 of 100,000, the likelihood of concurrence for both disorders in the same patient is approximately 1 in 80 million. Involvement of the vas deferens in cystic fibrosis raises the possibility of a fundamental embryologic basis that explains the pathogenesis of this association.- - - - - - - - - - ranking = 3.5keywords = embryo (Clic here for more details about this article) |