P-553 Response to controlled ovarian stimulation and preimplantation genetic testing for molecular disease (PGT-M) outcomes for Myotonic dystrophy type I (DM1) : A French multicentric study

Study question

Does ovarian response to controlled ovarian hyperstimulation (COH) is altered in female affected by DM1 ?

Summary answer

Ovarian response to COH is not altered in female affected by DM1 as compared to partners of affected males

What is known already

Myotonic dystrophy type 1 is the most common adult muscular dystrophy caused by a CTG trinucleotide repeat expansion which may expand across generation. As this pathology presents an autosomal dominant inheritance, PGT may be an option to achieve a pregnancy with healthy baby. There are conflicting reports about response to COH for affected female. Moreover, few data are available concerning the chance to have a healthy baby after PGT for couple with one member affected by DM1

Study design, size, duration

The present study is a retrospective observational study carried out from January 2006 through January 2020. This multicentric study was conducted in all the five centers performing PGT-M in France.

Participants/materials, setting, methods

A total of 229 couples started at least one COH cycle for the PGT procedure. The patient carrying the mutation was the female for 178 couples and the male for the 51 others. Overall, 648 COH cycles started and 560 oocytes retrieval for subsequent PGT were performed (430 for affected female and 130 for affected male). Parameters of ovarian response and PGT outcomes were compared according to the member affected by DM1.

Main results and the role of chance

Age and BMI at the first COH cycle were not significantly different between both group but female carried mutation presented lower AMH level than partner of affected male. The starting and total doses of gonadotrophin were significantly higher for mutated females. The number of retrieved and mature oocytes per cycle were not statistically different (12 [8–16] versus 11 [8–16] retrieved oocytes, p = 0.63 and 9 [6–13] versus 9 [6-13] mature oocytes, p = 0.73, respectively). In both group, more than 70% of oocyte retrieval led to embryo biopsy.

The proportion of started cycle allowing the obtention of at least one healthy embryo was significantly lower when the female was affected with DM1 (58.6% vs 70.4%, p = 0.012). In the female affected group, 49.7% of the cycles with oocytes retrieval lead to a fresh embryo transfer and a subsequent live birth rate per transfer of 21.4%. These results were not statistically different from the couple with affected male (58.5% of cycles with fresh embryo transfer (p = 0.08) and 23.6% live birth rate per transfer).

Overall, after fresh or frozen embryo transfer, 30.8% of females with DM1and 41.2% of parter of affected males had at least one live birth from PGT.

Limitations, reasons for caution

This a retrospective study included patients who were selected ovarian reserve parameters before PGT process. Moreover, the large time of inclusion may influence our conclusion.

Wider implications of the findings

Information provided herein extends knowledge about the current state of COH for DM1 affected female. Moreover, PGT results presented here allow to provide patients with proposer counseling before starting PGT process.

Trial registration number

CEROG-2020-GYN-0603

ESHRE PGT Consortium data collection XIX-XX: PGT analyses from 2016 to 2017†

STUDY QUESTION

What are the trends and developments in pre-implantation genetic testing (PGT) in 2016–2017 as compared to previous years?

SUMMARY ANSWER

The main trends observed in this 19th and 20th data set on PGT are that trophectoderm biopsy has become the main biopsy stage for PGT for aneuploidies (PGT-A) and that the implementation of comprehensive testing technologies is the most advanced with PGT-A.

WHAT IS KNOWN ALREADY

Since it was established in 1997, the ESHRE PGT Consortium has been collecting and analysing data from mainly European PGT centres. To date, 18 data sets and an overview of the first 10 years of data collections have been published.

STUDY DESIGN, SIZE, DURATION

The data for PGT analyses performed between 1 January 2016 and 31 December 2017 with a 2-year follow-up after analysis were provided by participating centres on a voluntary basis. Data were collected using a new online platform, which is based on genetic analysis as opposed to the former cycle-based format.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data on biopsy method, diagnostic technology and clinical outcome were submitted by 61 centres. Records with analyses for more than one PGT for monogenic/single gene defects (PGT-M) and/or PGT for chromosomal structural rearrangements (PGT-SR) indication or with inconsistent data regarding the PGT modality were excluded. All transfers performed within 2 years after the analysis were included enabling the calculation of cumulative pregnancy rates. Data analysis, calculations, figures and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

The current data collection from 2016 to 2017 covers a total of 3098 analyses for PGT-M, 1018 analyses for PGT-SR, 4033 analyses for PGT-A and 654 analyses for concurrent PGT-M/SR with PGT-A.

The application of blastocyst biopsy is gradually rising for PGT-M (from 8–12% in 2013–2015 to 19% in 2016–2017), is status quo for PGT-R (from 22–36% in 2013–2015 to 30% in 2016–2017) and has become the preferential biopsy stage for PGT-A (from 23–36% in 2013–2015 to 87% in 2016–2017). For concurrent PGT-M/SR with PGT-A, biopsy was primarily performed at the blastocyst stage (93%). The use of comprehensive diagnostic technology showed a similar trend with a small increased use for PGT-M (from 9–12% in 2013–2015 to 15% in 2016–2017) and a status quo for PGT-SR (from 36–58% in 2013–2015 to 50% in 2016–2017). Comprehensive testing was the main technology for PGT-A (from 66–75% in 2013–2015 to 93% in 2016–2017) and for concurrent PGT-M/SR with PGT-A (93%).

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the data submitted by 61 participating centres and do not represent worldwide trends in PGT. Details on the health of babies born were not provided in this manuscript.

WIDER IMPLICATIONS OF THE FINDINGS

Being the largest data collection on PGT in Europe/worldwide, the data sets provide a valuable resource for following trends in PGT practice.

STUDY FUNDING/COMPETING INTEREST(S)

The study has no external funding and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

ESHRE PGT Consortium data collection XVI-XVIII: cycles from 2013 to 2015

STUDY QUESTION

What are the trends and developments in preimplantation genetic testing (PGT) in 2013–2015 as compared to previous years?

SUMMARY ANSWER

The main trends observed in the retrospective data collections 2013–2015, representing valuable data on PGT activity in (mainly) Europe, are the increased application of trophectoderm biopsy at the cost of cleavage stage biopsy and the continuing expansion of comprehensive testing technology in PGT for chromosomal structural rearrangements and for aneuploidies (PGT-SR and PGT-A).

WHAT IS KNOWN ALREADY

Since it was established in 1997, the ESHRE PGT Consortium has been collecting data from international PGT centres. To date, 15 data sets and an overview of the first 10 years of data collections have been published.

STUDY DESIGN, SIZE, DURATION

Collection of (mainly) European data by the PGT Consortium for ESHRE. The data for PGT cycles performed between 1 January 2013 and 31 December 2015 were provided by participating centres on a voluntary basis. For the collection of cycle, pregnancy and baby data, separate, pre-designed MS Excel tables were used.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were submitted by 59, 60 and 59 centres respectively for 2013, 2014 and 2015 (full PGT Consortium members). Records with incomplete or inconsistent data were excluded from the calculations. Corrections, calculations, figures and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

For data collection XVI/XVII/XVIII, 59/60/59 centres reported data on 8164/9769/11 120 cycles with oocyte retrieval: 5020/6278/7155 cycles for PGT-A, 2026/2243/2661 cycles for PGT for monogenic/single gene defects, 1039/1189/1231 cycles for PGT-SR and 79/59/73 cycles for sexing for X-linked diseases. From 2013 until 2015, the uptake of biopsy at the blastocyst stage was mainly observed in cycles for PGT-A (from 23% to 36%) and PGT-SR (from 22% to 36%), alongside the increased application of comprehensive testing technology (from 66% to 75% in PGT-A and from 36% to 58% in PGT-SR).

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the 59/60/59 participating centres and may not represent worldwide trends in PGT. Data were collected retrospectively and no details of the follow-up on PGT pregnancies and babies born were provided.

WIDER IMPLICATIONS OF THE FINDINGS

Being the largest data collection on PGT worldwide, detailed information about ongoing developments in the field is provided.

STUDY FUNDING/COMPETING INTEREST(S)

The study has no external funding and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

ESHRE PGD Consortium data collection XIV-XV: cycles from January 2011 to December 2012 with pregnancy follow-up to October 2013

STUDY QUESTION

How does the data collection XIV-XV of the European Society of Human Reproduction and Embryology (ESHRE) PGD Consortium compare with the cumulative data for data collections I-XIII?

SUMMARY ANSWER

The 14th and 15th retrospective collection represents valuable data on PGD/PGS cycles, pregnancies and children: the main trend observed is the increased application of array technology at the cost of FISH testing in PGS cycles and in PGD cycles for chromosomal abnormalities.

WHAT IS KNOWN ALREADY

Since 1999, the PGD Consortium has collected, analysed and published 13 previous data sets and an overview of the first 10 years of data collections.

STUDY DESIGN, SIZE, DURATION

Data were collected from each participating centre using a FileMaker Pro database (versions 5-12). Separate predesigned FileMaker Pro files were used for the cycles, pregnancies and baby records. The study documented cycles performed during the calendar years 2011 and 2012 and follow-up of the pregnancies and babies born which resulted from these cycles (until October 2013).

PARTICIPANTS/MATERIALS, SETTINGS, METHOD

Data were submitted by 71 centres (full PGD Consortium members). Records with incomplete or inconsistent data were excluded from the calculations. Corrections, calculations and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

For data collection XIV-XV, 71 centres reported data for 11 637 cycles with oocyte retrieval (OR), along with details of the follow-up on 2147 pregnancies and 1755 babies born. A total of 1953 cycles to OR were reported for chromosomal abnormalities, 144 cycles to OR for sexing for X-linked diseases, 3445 cycles to OR for monogenic diseases, 6095 cycles to OR for PGS and 38 cycles to OR for social sexing. From 2010 until 2012, the use of arrays for genetic testing increased from 4% to 20% in PGS and from 6% to 13% in PGD cycles for chromosomal abnormalities; the uptake of biopsy at the blastocyst stage (from <1% up to 7%) was only observed in cycles for structural chromosomal abnormalities, alongside the application of array comparative genomic hybridization.

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the 71 participating centres and may not represent worldwide trends in PGD.

WIDER IMPLICATIONS OF THE FINDINGS

The annual data collections provide an important resource for data mining and for following trends in PGD/PGS practice.

STUDY FUNDING/COMPETING INTEREST(S)

None.

ESHRE PGD Consortium data collection XIII: cycles from January to December 2010 with pregnancy follow-up to October 2011

STUDY QUESTION

How do data in the 13th annual data collection (Data XIII) of the European Society of Human Reproduction and Embryology (ESHRE) PGD Consortium compare with the cumulative data for collections I-XII?

SUMMARY ANSWER

The 13th retrospective collection represents valuable data on PGD/PGS cycles, pregnancies and children: the main trend observed is the decrease in the routine implementation of PGS.

WHAT IS KNOWN ALREADY

Since 1999, the PGD Consortium has collected, analysed and published 12 data sets and an overview of the first 10 years of data collections.

STUDY DESIGN, SIZE, DURATION

Data were collected from each participating centre using a FileMaker Pro database (versions 5-11). Separate predesigned FileMaker Pro files were used for the cycles, pregnancies and baby records. The study documented cycles performed during the calendar year 2010 and follow-up of the pregnancies and babies born which resulted from these cycles (until October 2011).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were submitted by 62 centres (full PGD Consortium members). The submitted data were thoroughly analysed to identify incomplete data entries and corrections were requested from the participating centres. Records remaining with incomplete or inconsistent data were excluded from the calculations. Corrections, calculations and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

For data collection XIII, 62 centres reported data for 5780 cycles with oocyte retrieval (OR), along with details of the follow-up on 1503 pregnancies and 1152 babies born. A total of 1071 OR were reported for chromosomal abnormalities, 108 OR for sexing for X-linked diseases, 1574 OR for monogenic diseases, 2979 OR for preimplantation genetic screening and 48 OR for social sexing.

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the 62 participating centres and may not represent worldwide trends in PGD.

WIDER IMPLICATIONS OF THE FINDINGS

The annual data collections provide an important resource for data mining and for following trends in PGD practice.

STUDY FUNDING/COMPETING INTERESTS

None.

ESHRE PGD Consortium data collection XIII: cycles from January to December 2010 with pregnancy follow-up to October 2011

STUDY QUESTION

How do data in the 13th annual data collection (Data XIII) of the European Society of Human Reproduction and Embryology (ESHRE) PGD Consortium compare with the cumulative data for collections I-XII?

SUMMARY ANSWER

The 13th retrospective collection represents valuable data on PGD/PGS cycles, pregnancies and children: the main trend observed is the decrease in the routine implementation of PGS.

WHAT IS KNOWN ALREADY

Since 1999, the PGD Consortium has collected, analysed and published 12 data sets and an overview of the first 10 years of data collections.

STUDY DESIGN, SIZE, DURATION

Data were collected from each participating centre using a FileMaker Pro database (versions 5-11). Separate predesigned FileMaker Pro files were used for the cycles, pregnancies and baby records. The study documented cycles performed during the calendar year 2010 and follow-up of the pregnancies and babies born which resulted from these cycles (until October 2011).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were submitted by 62 centres (full PGD Consortium members). The submitted data were thoroughly analysed to identify incomplete data entries and corrections were requested from the participating centres. Records remaining with incomplete or inconsistent data were excluded from the calculations. Corrections, calculations and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

For data collection XIII, 62 centres reported data for 5780 cycles with oocyte retrieval (OR), along with details of the follow-up on 1503 pregnancies and 1152 babies born. A total of 1071 OR were reported for chromosomal abnormalities, 108 OR for sexing for X-linked diseases, 1574 OR for monogenic diseases, 2979 OR for preimplantation genetic screening and 48 OR for social sexing.

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the 62 participating centres and may not represent worldwide trends in PGD.

WIDER IMPLICATIONS OF THE FINDINGS

The annual data collections provide an important resource for data mining and for following trends in PGD practice.

STUDY FUNDING/COMPETING INTERESTS

None.

ESHRE PGD Consortium data collection XII: cycles from January to December 2009 with pregnancy follow-up to October 2010

STUDY QUESTION

How do data in the 12th annual data collection (Data XII) of the European Society of Human Reproduction and Embryology Preimplantation Genetic Diagnosis (PGD) Consortium compare with the cumulative data for collections I-XI?

SUMMARY ANSWER

Since the beginning of the data collections, there has been a steady increase in the number of cycles, pregnancies and babies reported annually.

WHAT IS KNOWN ALREADY

The PGD Consortium has collected, analysed and published 11 previous data sets since 1997.

STUDY DESIGN, SIZE, DURATION

Data were collected from each participating centre using a pre-designed FileMaker Pro database (versions 5-10). Separate FileMaker Pro files were used for the cycles, pregnancies and baby records. The study documented cycles performed during the calendar year 2009 and follow-up of the pregnancies and babies born which resulted from these cycles (until October 2010).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were submitted by 60 centres (full PGD Consortium members), and the blank files were distributed to each PGD Consortium member centre at the end of 2008. The submitted data were thoroughly analysed to identify incomplete data entries and corrections were requested from the participating centres. Records remaining with incomplete data were excluded from the calculations. Corrections, tables and calculations were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

For data collection XII, 60 centres reported data for 6160 cycles with oocyte retrieval (OR), along with details of the follow-up on 1607 pregnancies and 1238 babies born. A total of 870 OR were reported for chromosomal abnormalities, 113 OR for sexing for X-linked diseases, 1597 OR for monogenic diseases, 3551 OR for preimplantation genetic screening and 29 OR for social sexing.

LIMITATIONS, REASONS FOR CAUTION

These data cannot include every PGD cycle performed annually, and only indicate the trends in PGD worldwide.

WIDER IMPLICATION OF THE FINDINGS

The annual data collections provide an extremely valuable resource for data mining and for following trends in PGD practice.

STUDY FUNDING/COMPETING INTEREST(S)

None.

ESHRE PGD Consortium data collection XI: cycles from January to December 2008 with pregnancy follow-up to October 2009

The 11th report of the European Society of Human Reproduction and Embryology Preimplantation Genetic Diagnosis Consortium is presented, documenting cycles collected for the calendar year 2008 and follow-up of the pregnancies and babies born until October 2009 which resulted from these cycles. Since the beginning of the data collections, there has been a steady increase in the number of cycles, pregnancies and babies reported annually. For data collection XI, 53 centres have participated, reporting on 5641 cycles to oocyte retrieval (OR), along with details of the follow-up on 1418 pregnancies and 1169 babies born. A total of 774 OR were reported for chromosomal abnormalities, 96 OR for sexing for X-linked diseases, 1363 OR for monogenic diseases, 3401 OR for preimplantation genetic screening and 5 OR for social sexing. Data XI is compared with the cumulative data for data collections I-X.

The ESHRE PGD Consortium: 10 years of data collection

BACKGROUND

Since it was established in 1997, the ESHRE PGD Consortium has been collecting data from international preimplantation genetic diagnosis (PGD) centres. Ten papers have been published, including data from January 1997 to December 2007.

METHODS

The data collection originally used a hard-copy format, then an excel database and finally a FileMaker Pro database. The indications are divided into five categories: PGD for chromosome abnormalities, sexing for X-linked disease, PGD for single gene defects, preimplantation genetic screening (PGS) and PGD for social sexing. The main end-points are pregnancy outcome and follow-up of deliveries.

RESULTS

In data collection I, 16 centres contributed data, which increased to 57 centres by data X (average of 39 centres per data collection). These centres contributed data on over 27 000 cycles that reached oocyte retrieval. Of these cycles, 61% were for aneuploidy screening, 17% for single gene disorders, 16% for chromosomal abnormalities, 4% for sexing of X-linked disease and 2% for social sexing. Cumulatively, 5187 clinical pregnancies gave rise to 4140 deliveries and 5135 newborns (singletons: 3182, twins: 921, triplets: 37).

CONCLUSIONS

In this paper, we present an overview of the first 10 years of PGD data, highlighting trends. These include the introduction of laser-assisted biopsy, an increase in polar body and trophectoderm biopsy, new strategies, methodologies and technologies for diagnosis, including recently arrays, and the more frequent use of freezing biopsied embryos. The Consortium data reports represent a valuable resource for information about the practice of PGD.

ESHRE PGD consortium best practice guidelines for amplification-based PGD

In 2005, the European Society for Human Reproduction and Embryology (ESHRE) PGD Consortium published a set of Guidelines for Best Practice PGD to give information, support and guidance to potential, existing and fledgling PGD programmes. The subsequent years have seen the introduction of a number of new technologies as well as the evolution of current techniques. Additionally, in light of recent advice from ESHRE on how practice guidelines should be written and formulated, the Consortium believed it was timely to revise and update the PGD guidelines. Rather than one document that covers all of PGD, as in the original publication, these guidelines are separated into four new documents that apply to different aspects of a PGD programme, i.e. Organization of a PGD centre, fluorescence in situ hybridization-based testing, Amplification-based testing and Polar Body and Embryo Biopsy for PGD/preimplantation genetic screening. Here, we have updated the sections that pertain to amplification-based PGD. Topics covered in this guideline include inclusion/exclusion criteria for amplification-based PGD testing, preclinical validation of tests, amplification-based testing methods, tubing of cells for analysis, set-up of local IVF centre and Transport PGD centres, quality control/quality assurance and diagnostic confirmation of untransferred embryos.

ESHRE PGD consortium best practice guidelines for amplification-based PGD

In 2005, the European Society for Human Reproduction and Embryology (ESHRE) PGD Consortium published a set of Guidelines for Best Practice PGD to give information, support and guidance to potential, existing and fledgling PGD programmes. The subsequent years have seen the introduction of a number of new technologies as well as the evolution of current techniques. Additionally, in light of recent advice from ESHRE on how practice guidelines should be written and formulated, the Consortium believed it was timely to revise and update the PGD guidelines. Rather than one document that covers all of PGD, as in the original publication, these guidelines are separated into four new documents that apply to different aspects of a PGD programme, i.e. Organization of a PGD centre, fluorescence in situ hybridization-based testing, Amplification-based testing and Polar Body and Embryo Biopsy for PGD/preimplantation genetic screening. Here, we have updated the sections that pertain to amplification-based PGD. Topics covered in this guideline include inclusion/exclusion criteria for amplification-based PGD testing, preclinical validation of tests, amplification-based testing methods, tubing of cells for analysis, set-up of local IVF centre and Transport PGD centres, quality control/quality assurance and diagnostic confirmation of untransferred embryos.

ESHRE PGD Consortium data collection X: cycles from January to December 2007 with pregnancy follow-up to October 2008

The 10th report of the European Society of Human Reproduction and Embryology (ESHRE) PGD Consortium is presented, documenting cycles collected for the calendar year 2007 and follow-up of the pregnancies and babies born until October 2008 which resulted from these cycles. Since the beginning of the data collections there has been a steady increase in the number of cycles, pregnancies and babies reported annually. For data collection X, 57 centres participated, reporting on 5887 cycles to oocyte retrieval (OR), along with details of the follow-up on 1516 pregnancies and 1206 babies born. A total of 729 OR were reported for chromosomal abnormalities, 110 OR for sexing for X-linked diseases, 1203 OR for monogenic diseases, 3753 OR for preimplantation genetic screening and 92 OR for social sexing. Data X is compared with the cumulative data for data collections I-IX.

ESHRE PGD Consortium data collection IX: cycles from January to December 2006 with pregnancy follow-up to October 2007

The ninth report of the European Society of Human Reproduction and Embryology Preimplantation Genetic Diagnosis Consortium is presented documenting cycles collected for the calendar year 2006 and follow-up of the pregnancies and babies born until October 2007, which resulted from these cycles. Since the beginning of the data collections there has been a steady increase in the number of cycles, pregnancies and babies reported annually. For data collection IX, 57 centres have participated, reporting on 5858 cycles to oocyte retrieval (OR), along with details of the follow-up on 1437 pregnancies and 1206 babies born. Eight hundred and twelve ORs were reported for chromosomal abnormalities, 133 ORs for sexing for X-linked diseases, 931 ORs for monogenic diseases, 3900 ORs for preimplantation genetic screening and 82 ORs for social sexing. Data IX are compared with the cumulative data for data collections I-VIII.

Darwin--a mission to detect and search for life on extrasolar planets

The discovery of extrasolar planets is one of the greatest achievements of modern astronomy. The detection of planets that vary widely in mass demonstrates that extrasolar planets of low mass exist. In this paper, we describe a mission, called Darwin, whose primary goal is the search for, and characterization of, terrestrial extrasolar planets and the search for life. Accomplishing the mission objectives will require collaborative science across disciplines, including astrophysics, planetary sciences, chemistry, and microbiology. Darwin is designed to detect rocky planets similar to Earth and perform spectroscopic analysis at mid-infrared wavelengths (6-20 mum), where an advantageous contrast ratio between star and planet occurs. The baseline mission is projected to last 5 years and consists of approximately 200 individual target stars. Among these, 25-50 planetary systems can be studied spectroscopically, which will include the search for gases such as CO(2), H(2)O, CH(4), and O(3). Many of the key technologies required for the construction of Darwin have already been demonstrated, and the remainder are estimated to be mature in the near future. Darwin is a mission that will ignite intense interest in both the research community and the wider public.

ESHRE PGD Consortium data collection VIII: cycles from January to December 2005 with pregnancy follow-up to October 2006

The eighth report of the European Society of Human Reproduction and Embryology PGD Consortium is presented documenting cycles collected for the calendar year 2005 and follow-up of the pregnancies and babies born until October 2006 which resulted from these cycles. For the first time, the delivery rates for each indication are presented and also the pregnancy rates for each centre are reported anonymously. Since the first data collections, there has been a steady increase in the number of cycles, pregnancies and babies reported annually. For data collection VIII, 39 centres have participated, reporting on 3488 cycles to oocyte retrieval (OR), along with details of the follow-up on 845 pregnancies and 670 babies born. Five hundred and twenty OR were reported for chromosomal abnormalities, 108 OR for sexing for X-linked diseases, 500 OR for monogenic diseases, 2275 OR for preimplantation genetic screening and 85 OR for social sexing. Data VIII is compared with the cumulative data for data collections I-VII.

ESHRE PGD consortium data collection VII: cycles from January to December 2004 with pregnancy follow-up to October 2005

The seventh report of the ESHRE PGD Consortium is presented documenting cycles collected for the calendar year 2004 and follow-up of the pregnancies and babies born subsequent to these cycles up to October 2005. Since the beginning of the data collections, there has been a steady increase in the number of cycles, pregnancies and babies reported. For data collection VII, 45 centres have participated, reporting on 3358 cycles to oocyte retrieval (OR), 679 pregnancies and 528 babies born. Five hundred and fifty nine OR were reported for chromosomal abnormalities, 113 OR for sexing for X-linked diseases, 520 OR for monogenic diseases, 2087 OR for PGS, and 79 OR for social sexing. Data VII is compared with the cumulative data for data collections I-VI.

ESHRE PGD Consortium data collection VI: cycles from January to December 2003 with pregnancy follow-up to October 2004

The sixth report of the ESHRE PGD Consortium is presented, relating to cycles collected for the calendar year 2003 and follow-up of the pregnancies and babies born up to October 2004. Since the beginning of the data collections, there has been a steady rise in the number of cycles, pregnancies and babies reported. For this report, 50 centres participated, reporting on 2984 cycles, 501 pregnancies and 373 babies born. Five hundred and twenty-nine cycles were reported for chromosomal abnormalities, 516 cycles were reported for monogenic diseases, 137 cycles were reported for sexing for X-linked diseases, 1722 cycles were reported for preimplantation genetic screening (PGS) and 80 cycles were reported for social sexing. Data VI is compared to the cumulative data for data collections I-V.

Strategies and outcomes of PGD of familial adenomatous polyposis

Owing to adult onset of hereditary cancer, prenatal diagnosis (PND) raises numerous ethical issues on the acceptability to terminate an affected pregnancy (TOP). PND for these disorders is often considered as unacceptable by couples as well as geneticists and legal or ethical authorities, but preimplantation genetic diagnosis (PGD), even if subject to controversy, seems to be a more acceptable option. Therefore, many couples, who do not want to transmit their cancer to their children, consider PGD as their only reproductive option. This article describes our experience of PGD for familial adenomatous polyposis (FAP). Twelve couples were referred between 2000 and 2005. We developed PGD tests to detect the mutation alone, but we rapidly set up multiplex PCR combining mutation detection and indirect diagnosis. Finally, we set up duplex and triplex indirect diagnoses to be able to offer a PGD, whatever mutation was involved in familial cases. PGD strategies were based on (i) a new double allele-specific PCR approach (D-ARMS) allowing the detection of the wild-type and mutated allele; (ii) PCR fragments sizing and (iii) restriction length polymorphisms. For the 12 referrals, we developed eight tests, and 11 cycles have been performed for four couples, resulting in eight embryo transfers and five pregnancies, with the birth of one healthy boy and two ongoing pregnancies. We are now able to propose PGD to most couples at risk of transmitting FAP to their offspring, whether the mutation is familial or occurred de novo.

ESHRE PGD Consortium data collection V: Cycles from January to December 2002 with pregnancy follow-up to October 2003

The fifth report of the ESHRE PGD Consortium is presented (data collection V). For the first time, the cycle data were collected for one calendar year (2002) in the following October, so that data collection was complete for pregnancies and babies. The data were collected using a Filemaker Pro database and divided into referrals, cycles, pregnancies and babies. There are currently 66 active centres registered with the consortium; however, the data presented here were obtained from 43 centres and included 1603 referrals, 2219 cycles, 485 pregnancies and 382 babies born. The cycle data were divided into preimplantation genetic diagnosis (PGD) for inherited disorders (including chromosome abnormalities, sexing for X-linked disease and monogenic disorders), aneuploidy screening (PGS) and the use of PGD for social sexing. Data collection V is compared with the previous cumulative data collection (I-IV), which comprised 4058 PGD/PGS cycles that reached oocyte retrieval.

ESHRE PGD Consortium ‘Best practice guidelines for clinical preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS)’

Among the many educational materials produced by the European Society of Human Reproduction and Embryology (ESHRE) are guidelines. ESHRE guidelines may be developed for many reasons but their intent is always to promote best quality practices in reproductive medicine. In an era in which preimplantation genetic diagnosis (PGD) has become a reality, we must strive to maintain its efficacy and credibility by offering the safest and most effective treatment available. The dominant motivators for the development of current comprehensive guidelines for best PGD practice were (i) the absence of guidelines and/or regulation for PGD in many countries and (ii) the observation that no consensus exists on many of the clinical and technical aspects of PGD. As a consequence, the ESHRE PGD Consortium undertook to draw up guidelines aimed at giving information, support and guidance to potential, fledgling and established PGD centres. The success of a PGD treatment cycle is the result of great attention to detail. We have strived to provide a similar level of detail in this document and hope that it will assist staff in achieving the best clinical outcome for their patients.

ESHRE PGD Consortium data collection IV: May–December 2001

The ESHRE PGD Consortium was formed in 1997 to survey the practice of preimplantation genetic diagnosis (PGD). Since then, three reports have been published giving an overview on PGD from an ever-increasing number of centres and reporting on an increasing number of PGD cycles and pregnancies and babies born after PGD. After these initial influential publications, important shortcomings were identified primarily on the method of data collection, i.e. with Excel spreadsheets, and in the timing of the collection (cycles were collected in a different time frame from pregnancies and babies, making the follow-up of cycles very difficult). This is why the Steering Committee has made a major investment in developing and implementing a new database in FileMaker Pro 6. It was also decided that cycles would be collected from one calendar year, as well as the pregnancies and babies ensuing from that particular calendar year. This gave us the opportunity to take a closer look at the data collected earlier, and to attempt to improve their quality. This is a report on the corrected data from the first three data collections (I-III) as well as the result of the last data collection (IV) that was completely carried out using the new database.

[Preimplantation genetic diagnosis of monogenic diseases]

Preimplantation genetic diagnosis (PGD) is an alternative to prenatal diagnosis allowing the detection of genetic diseases on IVF embryos before their transfer into the uterus and before the pregnancy. The aim of this procedure is to obtain unaffected or carrier embryos in order to avoid the burden of termination of pregnancy after prenatal diagnosis for couples at risk of transmitting particularly severe genetic disorders to their offspring. For monogenic diseases, PGD is most often based on single blastomere amplification by polymerase chain reaction (PCR). More than a decade after the first births, the possibilities of diagnosis for monogenic diseases have considerably increased. As for molecular biology and conventional diagnosis, the technologies and strategies for PGD are continually improved, with for instance introduction of fluorescent PCR or multiplex amplification. In this review, we describe several approaches for PGD of monogenic diseases, followed by an overview of the French practice, particularly in our lab.

[Twin birth after preimplantation diagnosis for cystic fibrosis]

OBJECTIVE

Cystic fibrosis is a common autosomal recessive disease most often caused by a deletion (delta F508) in the CFTR gene. It is the most common indication for preimplantaion genetic diagnosis which allows genetic analysis of embryos obtained after in vitro fertilization and transfer of unaffected embryos into the patient's uterus.

PATIENTS AND METHODS

We report the first preimplantation genetic diagnosis performed in Strasbourg for a couple at risk of having a child affected by severe cystic fibrosis due to a homozygous delta F508 mutation. Three days after fertilisation, embryos obtained after intra-cytoplasmic testiculare sperm injection were biopsied and analysed. PCR amplification of the genomic fragment containing the delta F508 locus allowed detection of the delta F508 mutation and transfer only of the unaffected embryos.

RESULTS

Three embryos were transferred after this preimplantation genetic diagnosis. A twin pregnancy was obtained and the babies born from this cycle are both exempt from the mutation.

CONCLUSIONS

Preimplantation genetic diagnosis for the cystic fibrosis delta F508 mutation is now available in our centre. In this report, we could resolve both the problem of infertility and the risk of transmission of a severe form of cystic fibrosis. Preimplantation genetic diagnosis is also available for other mutations involved in cystic fibrosis and also for other genetic diseases.

Allele-specific amplification for preimplantation genetic diagnosis (PGD) of spinal muscular atrophy

We have developed a new allele-specific amplification method for the preimplantation genetic diagnosis (PGD) of spinal muscular atrophy (SMA; Werdnig-Hoffmann disease) from a single cell. This method is based on the detection of the deletion of exon 7 of the telomeric copy of the survival motor neurone (SMN(t)) gene. An oligonucleotide was designed to be specific to the SMN(t) nucleotidic sequence with exonic mismatch G (for SMN(t))-->A (for SMN(c)) at its 3' end. This test produces reliable PCR products in 95% of single lymphoblasts (85/88) tested as well as in 16/16 blastomeres from normal controls. Specificity analysis showed that we were able to detect homozygous deletion of the SMN(t) gene in 99% of single lymphoblasts (103/104) from a SMA patient. No contamination was detected in 68 blanks tested. Multiple cell and DNA dilution analysis revealed that the test is accurate and specific up to 100 pg DNA and should thus also be suitable for PGD at the blastocyst stage. This rapid procedure requires a single round of fluorescent PCR and no restriction digestion, while previously described single cell methods include nested PCR followed by restriction enzyme digestion. Two PGD cycles for SMA using this procedure were performed in our centre.

A clinical and genetic study of a manifesting heterozygote with X-linked myotubular myopathy

X-linked myotubular myopathy (XLMTM) characteristically causes severe or fatal muscle weakness in male infants. Mutations in the gene MTM1, encoding the protein myotubularin, can be identified in most families. Prior to this report, XLMTM was thought not to cause symptomatic manifestations in female carriers. We describe an adult female from a large family with typical XLMTM. The patient had progressive disabling muscle weakness of later onset and lesser severity than that observed in affected males. The distribution of weakness resembled typical XLMTM with facial weakness, marked limb-girdle weakness, respiratory muscle involvement and dysphagia. Analysis of the MTM1 gene identified a heterozygous missense mutation (G378R) within the highly conserved tyrosine phosphatase site of myotubularin. We did not identify significantly skewed X-inactivation. We conclude that XLMTM is capable of causing significant disability in heterozygotes.

Identification of novel mutations in the MTM1 gene causing severe and mild forms of X-linked myotubular myopathy

X-linked myotubular myopathy (XLMTM) is a congenital muscular disease characterized by severe hypotonia and generalized muscle weakness, leading in most cases to early postnatal death. The gene responsible for the disease, MTM1, encodes a dual specificity phosphatase, named myotubularin, which is highly conserved throughout evolution. To date, 139 MTM1 mutations in independent patients have been reported, corresponding to 93 different mutations. In this report we describe the identification of 21 mutations (14 novel) in XLMTM patients. Seventeen mutations are associated with a severe phenotype in males, with death occurring mainly before the first year of life. However, four mutations-three missense (R241C, I225T, and novel mutation P179S) and one single-amino acid deletion (G294del)-were found in patients with a much milder phenotype. These patients, while having a severe hypotonia at birth, are still alive at the age of 4, 7, 13, and 15 years, respectively, and display mild to moderate muscle weakness.

Evolution of the Friedreich's ataxia trinucleotide repeat expansion: founder effect and premutations

Friedreich's ataxia, the most frequent inherited ataxia, is caused, in the vast majority of cases, by large GAA repeat expansions in the first intron of the frataxin gene. The normal sequence corresponds to a moderately polymorphic trinucleotide repeat with bimodal size distribution. Small normal alleles have approximately eight to nine repeats whereas a more heterogeneous mode of large normal alleles ranges from 16 to 34 GAA. The latter class accounts for approximately 17% of normal alleles. To identify the origin of the expansion mutation, we analyzed linkage disequilibrium between expansion mutations or normal alleles and a haplotype of five polymorphic markers within or close to the frataxin gene; 51% of the expansions were associated with a single haplotype, and the other expansions were associated with haplotypes that could be related to the major one by mutation at a polymorphic marker or by ancient recombination. Of interest, the major haplotype associated with expansion is also the major haplotype associated with the larger alleles in the normal size range and was almost never found associated with the smaller normal alleles. The results indicate that most if not all large normal alleles derive from a single founder chromosome and that they represent a reservoir for larger expansion events, possibly through "premutation" intermediates. Indeed, we found two such alleles (42 and 60 GAA) that underwent cataclysmic expansion to pathological range in a single generation. This stepwise evolution to large trinucleotide expansions already was suggested for myotonic dystrophy and fragile X syndrome and may relate to a common mutational mechanism, despite sequence motif differences.

Transition from premutation to full mutation in fragile X syndrome is likely to be prezygotic

In the fragile X syndrome, the transition from unmethylated moderate expansions of the CGG repeat (premutations) to methylated large expansions (full mutations) occurs only through maternal transmission. The risk of such transition is highly correlated with the size of the maternal premutation (PM), being very low for small PM alleles (approximately 60 repeats), to 100% for alleles above 100 repeats. The timing of this transition was the object of much speculation. A postzygotic transition was proposed as a preferred model, based on the observation that males with full mutation (FM) have PM in sperm. Analysis of tissues from affected fetuses, including additional data reported here, indicate that such a putative postzygotic transition would have to occur very early in embryogenesis and most likely before determination of germ cell lineage. At least 15% of carriers of a FM show a significant proportion of white blood cells carrying a PM (mutation mosaics). We performed a simulation study showing that, if transition to FM is postzygotic, one should observe a much higher proportion of such mosaics in offspring of mothers with small PMs. This was compared with the actual pattern observed in 212 mutated offspring of 112 PM carrier mothers. We found no effect of maternal PM size on incidence of mosaicism in leucocytes. We propose that this is strong, albeit indirect evidence against a postzygotic transition to FM. A transition at an early morula stage (before day 3) cannot, however, be formally excluded.

[Fragile X syndrome is still unrecognized: efficacy of molecular diagnosis in mentally retarded probands]

BACKGROUND

The fragile X mental retardation syndrome is the most common cause of inherited mental retardation. Identification of the unstable mutation responsible for the disease has allowed the design of a fully reliable molecular test for the diagnosis of the disease and for genetic counselling (identification of clinically normal carriers and prenatal diagnosis). We started in July 1991 to search for the mutation in mentally retarded probands, with no known cause for their phenotype. We present the results of a 42-month experience.

POPULATION AND METHODS

One thousand and one hundred fourty-nine probands were analysed. In case of a positive diagnosis, an extension of the molecular study to relatives was proposed. DNA samples were studied by Southern blot following EcoRI or EcoRI + EagI digestion. Clinical data were collected from referring clinicians.

RESULTS

Seventy-three carriers of a full mutation were identified, belonging to 52 families. The mean age of the fragile X probands was 16 +/- 14 years, which is very surprising for a disease that causes significant manifestations by the age of 2 to 3 years. This indicates an insufficient knowledge about this disease in France. Most of the demands for the test were from clinical geneticists. This diagnosis is of major importance for genetic counselling, as illustrated by the following study of 108 women at risk in these families.

CONCLUSIONS

The importance of an early diagnosis followed by an extended family study, for carrier screening and prevention of this severe disease, justifies molecular testing on any child with mental retardation or significant language delay of unknown cause, in the absence of clinical signs formally excluding a fragile X diagnosis.

Genetic transmission of susceptibility to cancer in families of children with soft tissue sarcomas

BACKGROUND

This article presents analysis of clinical and family data for 239 patients with childhood soft tissue sarcoma (STS) treated at the Institut Gustave Roussy in Villejuif.

METHODS

A molecular study was performed to detect germline p53 mutations in the 44 families in which at least 1 relative developed cancer before the age of 46 or in which the proband had a second neoplasm. Mutations were found in five families. Standardized incidence ratio calculation and segregation analysis were used to study cancer occurrence in 4448 relatives, including first- and second-degree relatives and first cousins.

RESULTS

An excess of brain tumors was observed in all relatives, and of breast carcinoma and STS in first-degree relatives of patients with STS. An excess of breast carcinoma was observed only in young mothers of patients with rhabdomyosarcoma. This excess might be mostly linked to the presence of a germline p53 mutation because it was no more significant when excluding families in which such a mutation existed. No association between breast carcinoma in the mother and rhabdomyosarcoma of the genitourinary tract in the proband was observed. This should be kept in mind when developing a screening strategy for breast carcinoma in mothers of patients with STS. Segregation analysis showed evidence for transmission of an autosomal dominant gene with complete penetrance by the age of 84. The genetic component was explained primarily by p53 germline mutations.

CONCLUSIONS

These results show that most relatives of patients with STS are at the same risk for cancer as the general population.

Cancers in relatives of children with non-Hodgkin's lymphoma

We undertook a family study of children treated at the Institute Gustave-Roussy in France to investigate a familial aggregation of cancer in the families of children with non-Hodgkin's lymphoma (NHL). We obtained family dat for 284 children with NHL. Using the Standardized Incidence Ratio, we compared the observed and expected number of families with at least one proband relative affected by cancer at a young age (before 46 years). We found a small but non-significant excess of all tumors in first-degree relatives (SIR = 1.3, 95% CI = 0.7-2.3) explained by a small but non-significant excess of hematological malignancies (SIR = 1.5, 95% CI = 0.2-5.5), particularly Hodgkin's disease and leukemia, and of osteosarcoma (SIR = 7.5, 95% CI = 0.1-41.4). This is probably a lower bound of the SIR, because the expected number of families was estimated from cancer incidence in France between 1978 and 1982, whereas most cancers occurred before this period. Other tumors were not in excess in first-degree relatives.

ARCAD: a method for estimating age-dependent disease risk associated with mutation carrier status from family data

We present ARCAD, a method to estimate the disease risk associated with mutation carrier status using data on families ascertained by affected individuals, in which a germline mutation has been detected. Because the event of interest, the age of onset, is a censored variable, the method uses the survival analysis approach to formulate the likelihood. Provided that selection criteria are clearly defined, the ascertainment bias is removed by including a correction term in the likelihood computation. We simulated family data and selected those with a proband affected before age 17, and at least one or at least two relatives affected before age 46. We show that including the correction for the ascertainment provides reliable estimates of the risk, even when many individuals are not tested for the mutation. An application to cancer risk and germline p53 mutations is presented. We routinely investigate the p53 status for all the children treated in the Department of Pediatric Oncology at the Institute Gustave Roussy, whose family displays at least one relative affected by cancer before age 46. We identified 5 families with an inherited germline p53 mutation. The risk for any cancer for a mutation carrier estimated by ARCAD was 42% within the age class 0-16 years, 38% within the age class 17-45 years, and 63% after 45 years, with a lifetime risk of 85%. These risks are almost entirely explained by the occurrence of the six most frequent cancers encountered in the Li-Fraumeni syndrome.

The French Wilms' tumour study: no clear evidence for cancer prone families

Wilms' tumour of the kidney is known to occur in Beckwith-Wiedemann syndrome. It has also been described in four cancer prone families displaying Li-Fraumeni syndrome but it is not usually considered to be part of this syndrome. In order to detect particular familial cancer aggregations associated with this tumour, we studied the cancer incidence and mortality among relatives of the 501 Wilms' tumour patients in the French Wilms' Tumour Study. We found no familial association with breast cancer or soft tissue sarcomas which are the most common cancers in the Li-Fraumeni syndrome. However, we found two significant familial associations of Wilms' tumour with bone cancers on the one hand and with brain tumours on the other hand. These associations could reflect a small proportion of families segregating for some susceptibility gene. This should then be confirmed at the molecular level.