[Cancer genetics: estimation of the needs of the population in France for the next ten years].

Organised since 1990 in France, cancer genetics has been strengthened since 2003 by the programme "Plan Cancer" which resulted in an improvement of the organisation of activities. The aim of this review is to present an update of the estimation of the needs of the population in this field for the next ten years, provided by a group of experts mandated by the French National Cancer Institute. Identification and management of major hereditary predispositions to cancer have a major impact on decrease in mortality and incidence.

Fathers over 40 and increased failure to conceive: the lessons of in vitro fertilization in France.

Objective: To investigate paternal age effect mediated by biological modifications with use of data from assisted reproductive technologies.

Design: National IVF registry.

Setting: Fifty nine French IVF centers.

Functional disomy of Xp including duplication of DAX1 gene with sex reversal due to t(X;Y)(p21.2;p11.3).

Translocations involving the short arms of the X and Y in human chromosomes are uncommon. One of the best-known consequences of such exchanges is sex reversal in 46,XX males and some 46,XY females, due to exchange in the paternal germline of terminal portions of Xp and Yp, including the SRY gene. Translocations of Xp segments to the Y chromosome result in functional disomy of the X chromosome with an abnormal phenotype and sex reversal if the DSS locus, mapped in Xp21, is present.

How can the genetic risks of embryo donation be minimized? Proposed guidelines of the French Federation of CECOS (Centre d'Etude et de Conservation des Oeufs et du Sperme).

Embryo donation is now an acceptable practice which offers new possibilities to many infertile couples wishing to procreate. In France, embryo donation, like gamete donation, is controlled by law, but its application has been poorly developed because too many questions remained unsolved and because of the lack of practical guidelines. Here we report the results of the debate which took place within the Genetics Commission of the French Federation of CECOS and the proposed recommendations which followed, emphasizing the genetic background to be considered for embryo donation.

[Value of karyotyping women patients of couples referred for sterility].

It has been known for some 25 years that there is a causal relation between chromosomal aberrations and male infertility and that the major indication for karyotyping an infertile man is still usually an abnormal sperm analysis. The value of karyotyping women in the routine work-up of couples referred for sterility has long been debated. A French recent cytogenetic study found an overall increased frequency of chromosomal aberrations in the female and confirmed that in some cases of poor reproductive outcome there may be a contribution of maternal chromosome aberrations.

Cerebro-costo-mandibular syndrome in a father and a female fetus: early prenatal ultrasonographic diagnosis and autosomal dominant transmission.

Ultrasonography in a female fetus revealed cystic cervical hygroma, severe micrognathia, and vertebral and upper limb anomalies suggestive of cerebro-costo-mandibular syndrome (CCMS) which was diagnosed ultrasonographically at 16 weeks' gestation. The father is affected and presents with a Pierre Robin sequence, short stature and typical costovertebral anomalies. CCMS is a rare and severe disorder.

[X-linked recessive chondrodysplasia punctata. Cytogenetic study and role of molecular biology].

Unlabelled: Among the many acquired or constitutional causes of chondrodysplasia punctata, the X-linked recessive form is well individualized.

Case Report: A male newborn presented a dysmorphic syndrome with a marked nasal hypoplasia, a macroglossia and a short neck. The diagnosis of chondrodysplasia punctata was made by radiography whereas the chromosomal chart revealed the existence of an additional Y fragment in Xpter, effectuating a partial disomy Yp and a monosomy Xpter.

Chromosomal factors of infertility in candidate couples for ICSI: an equal risk of constitutional aberrations in women and men.

To assess the frequency of chromosomal aberrations in French candidates for intracytoplasmic sperm injection (ICSI), and to explore the existence of a female chromosomal factor in some cases of couple infertility, a collaborative retrospective clinical and cytogenetic study was performed, launched by the Association des Cytogénéticiens de Langue Franciaise (ACLF). The karyotypes of 3208 patients [2196 men (68.4%), 1012 (31.

[Results of oocyte donation in France (Study Group on Oocyte Donation)].

The French study group on oocyte donation, named GEDO, reports the results concerning the oocyte donation activity in France during 1998, including information from all the centers in effective operation except one. These data describe the recipients' and donors' situation and give the analysis of the results obtained.

[1998 french results on medically assisted reproduction with gamete cryopreservation and donation. French Federation of CECOS].

During the year 1998, the French Federation of CECOS recorded the results of the 23 CECOS centers and IFRAERES in Toulouse. 1,573 first demands of procreation with sperm donors were registed (versus 1,620 in 1997). From 9,339 cycles (AID or IVFD), 1351 pregnancies were obtained, scoring the identical amount in terms of pregnancies as in 1997 but with less 9% in terms of cycles.

Informed consent to serum screening for Down syndrome: are women given adequate information?

To assess the information given to women during a maternal serum screening (MSS) programme, we prospectively applied a questionnaire to 504 pregnant women attending for amniocentesis after a screen-positive result. The survey based on 200 usable questionnaires (39.7 per cent of our study population) showed that MSS was imposed as mandatory by 41.

[Results of oocyte donation in France (GEDO)].

The French study group on oocyte donation, named GEDO, reports the results concerning the oocyte donation activity in France from 1994 to 1997, with the informations of all the centers, in effective operation. These data describe the recipients' and donors' situation and give the analysis of the results obtained.

[1997 results of medical assisted procreation with third party donations and autopreservation. CECOS French Federation].

During the year 1997, the French Federation of CECOS recorded the results of the 23 CECOS centers and IFRAERES in Toulouse. 1620 first demands of procreation with sperm donors were registed (versus 1,690 in 1996) but only 3,235 patients received at least one donation in the year, 22% less than 1996. From 10,935 cycles (AID or IVFD), 1,333 pregnancies were obtained, scoring the identical amount in terms of pregnancies as in 1996 but with less 30% in terms of cycles.

Multicentre approaches to donor insemination in the French CECOS Federation: nationwide evaluation, donor matching, screening for genetic diseases and consanguinity. Centre d'Etudes et de Conservation des Oeufs et du Sperme humain.

The French CECOS Federation collates the results of its 22 sperm banks and provides annual reports on their activity. These records allow studies on many different aspects; annual nationwide evaluation, matching of donors and recipients, follow-up of pregnancies, research into artificial procreation, and natural fertility. Risk of transmitted hereditary disease is minimised by genetic screening which establishes the genealogy of donor candidates and includes karyotyping and other biological investigations when a particular risk is suspected.

Pregnancy outcome after artificial insemination or IVF with frozen semen donor: a collaborative study of the French CECOS Federation on 21,597 pregnancies.

Objective: To assess pregnancies and conceptus after artificial insemination (AID) or IVF with frozen semen donor (IVF-D) on sufficiently large study population in order to distinguished minor variations.

Study Design: From 1987 to 1994, all pregnancies obtained after AID or IVF-D were registered prospectively in the French CECOS Federation data base. Different factors were recorded for this study: first menarche age of the recipient women, cycle length, insemination date in the conception cycle, maternal age at delivery, hormonal treatments, donor age, sperm conservation length and follow up of the pregnancy: miscarriage, tubal pregnancy, time at delivery, sex of the foetus, weight, malformation.

Incidence of birth defects after artificial insemination with frozen donor spermatozoa: a collaborative study of the French CECOS Federation on 11,535 pregnancies.

Artificial insemination using cryogenically preserved spermatozoa has been widely used in human reproduction for several decades. No evaluation of the resulting pregnancies and conceptions has been undertaken in sufficiently large study populations for minor variations to be distinguished. This study involves 11,535 pregnancies conceived by artificial insemination using donor spermatozoa and followed from the time that pregnancy was diagnosed.

Analysis of germline variation at the FMR1 CGG repeat shows variation in the normal-premutated borderline range.

In order to characterize the dynamics of CGG repeat instability at the fragile X syndrome locus (FMR1 gene), we have used small pool PCR to estimate the mutation rate within germline (sperm) and somatic tissue (leukocytes) of two normal males, one carrying the most common 29 CGG repeats allele, the other carrying a borderline normal-premutated allele of 55 repeats. Large contractions and moderate expansions of the repeat were found in sperm and blood for the 55 repeat allele while almost no variation was found in sperm or blood with the 29 repeat allele. Somatic blood DNA exhibited fewer expansions and contractions than sperm.

Maternal serum screening for fetal Down's syndrome, a retrospective study.

A retrospective study of the different biochemical markers used in screening for Down's syndrome was carried out on serum from 18,600 women between their 15th and 18th week of pregnancy. Thirty-two sera were from women with fetal Down's syndrome. The retrospective study of these 32 sera involves: (a) the screening of the maternal serum concentrations of human chorionic gonadotropin (hCG) and of alpha-fetoprotein (AFP); (b) the evaluation of the risk of Down's syndrome when screening maternal serum concentrations of hCG alone, then the combination of the two markers and finally the maternal serum concentrations of unconjugated estriol (uE3).

Molecular analysis of a ring chromosome X in a family with fragile X syndrome.

The phenotypically normal sister of a patient affected by fragile X syndrome was referred for genetic counselling and was found to carry a mosaic karyotype 46,X,r(X)/45,X. Because the probability of the simultaneous chance occurrence of fragile X syndrome and a ring chromosome X in the same family is very low, we postulated that the breakpoint of the ring chromosome X originated in the cytogenetic break in Xq27.3 responsible for fragile X syndrome.

[Paternal age and pregnancy issues. The CECOS experience].

From a collaborative study of the French "Federation des CECOS" who collected the follow up of 11,535 pregnancies, the effect of parental age on the offspring is studied. A significant influence of the donor's age is demonstrated for the occurrence of trisomy 21 (37.4 +/- 7.

[Contribution of applied cytogenetics to medically assisted procreation].

The cytogenetic studies of gametes and embryos reveal the incidence of chromosomic abnormalities in medically assisted pregnancies. When extended to natural fecundation, these data enable a better comprehension of the place and the role of the selection in the quality of the conceptus.

[Study of the choice between sampling of the chorionic villi and the amniotic fluid in prenatal diagnosis].

We are reporting the results of a 21-month study during which 653 couples were seen in consultation at the prenatal diagnostic center of the University Hospital in Amiens, referred by their physician. 171 patients presented a theoretical term under 11 weeks of amenorrhea, for whom the choice between chorionic villi biopsy or amniotic fluid tap was possible. The different situations and results are compared for each method.