Molecular characterization of 39 de novo sSMC: contribution to prognosis and genetic counselling, a prospective study.

Small supernumerary marker chromosomes (sSMCs) are structurally abnormal chromosomes that cannot be characterized by karyotype. In many prenatal cases of de novo sSMC, the outcome of pregnancy is difficult to predict because the euchromatin content is unclear. This study aimed to determine the presence or absence of euchromatin material of 39 de novo prenatally ascertained sSMC by array-comparative genomic hybridization (array-CGH) or single nucleotide polymorphism (SNP) array. Cases were prospectively ascertained from the study of 65,000 prenatal samples [0.060%; 95% confidence interval (CI), 0.042-0.082]. Array-CGH showed that 22 markers were derived from non-acrocentric markers (56.4%) and 7 from acrocentic markers (18%). The 10 additional cases remained unidentified (25.6%), but 7 of 10 could be further identified using fluorescence in situ hybridization; 69% of de novo sSMC contained euchromatin material, 95.4% of which for non-acrocentric markers. Some sSMC containing euchromatin had a normal phenotype (31% for non-acrocentric and 75% for acrocentric markers). Statistical differences between normal and abnormal phenotypes were shown for the size of the euchromatin material (more or less than 1 Mb, p = 0.0006) and number of genes (more or less than 10, p = 0.0009). This study is the largest to date and shows the utility of array-CGH or SNP array in the detection and characterization of de novo sSMC in a prenatal context.

Pregnancy outcomes of prenatally diagnosed Turner syndrome: a French multicenter retrospective study including a series of 975 cases.

OBJECTIVES: The objectives of this study were to report pregnancy outcomes after prenatal diagnosis of Turner syndrome (TS) and to compare and assess termination of pregnancy rates during two periods. The intervals selected were before and after 1997 when multidisciplinary centers for prenatal diagnosis (MCPDs) were established in France. METHODS: A database of 975 cases of TS diagnosed between 1980 and 2012 was created from 21 French cytogenetics laboratories. For each case, the karyotype indication, maternal age, year of prenatal testing, sampling procedure, karyotype, associated ultrasound findings, and outcomes were recorded. RESULTS: Karyotypes were mainly performed because of abnormal sonographic findings (84%). Before 1997, there were no changes in the rate of termination (90%) of affected fetuses. After 1997, the rate fell to 80%. This decrease was mainly observed in cases of mosaicism, incidental diagnosis, and in later gestations. US abnormalities were more likely to be associated with a full 45,X karyotype. CONCLUSION: There was an evolution in the way genetic counseling was performed following prenatal diagnosis of Turner syndrome that coincided with the opening of MCPDs in France. This resulted in a decrease in the rate of termination of affected fetuses.

A French collaborative survey of 272 fetuses with 22q11.2 deletion: ultrasound findings, fetal autopsies and pregnancy outcomes.

OBJECTIVE: The 22q11.2 deletion (del22q11.2) is one of the most common microdeletions. We performed a collaborative, retrospective analysis in France of prenatal diagnoses and outcomes of fetuses carrying the del22q11.2. METHODS: A total of 272 fetuses were included. Data on prenatal diagnosis, ultrasound findings, pathological features, outcomes and inheritance were analyzed. RESULTS: The mean time of prenatal diagnosis was 25.6 ± 6 weeks of gestation. Most of the diagnoses (86.8%) were prompted by abnormal ultrasound findings [heart defects (HDs), in 83.8% of cases]. On fetal autopsy, HDs were again the most common disease feature, but thymus, kidney abnormalities and facial dysmorphism were also described. The deletion was inherited in 27% of cases. Termination of pregnancy (TOP) occurred in 68.9% of cases and did not appear to depend on the inheritance status. However, early diagnosis was associated with a higher TOP rate. CONCLUSION: This is the largest cohort of prenatal del22q11.2 diagnoses. As in postnatally diagnosed cases, HDs were the most frequently observed abnormalities. However, thymus and kidney abnormalities and polyhydramnios should also be screened for in the prenatal diagnosis of del22q11.2. Only the time of diagnosis appeared to be strongly associated with the pregnancy outcome: the earlier the diagnosis, the higher the TOP rate.

The feasibility of fertility preservation in adolescents with Klinefelter syndrome.

STUDY QUESTION: Is fertility preservation feasible after the onset of puberty in adolescents with Klinefelter syndrome (KS)? SUMMARY ANSWER: Fertility preservation counseling should be an integral part of the care of XXY adolescents. Frozen ejaculated or testicular spermatozoa and even frozen immature germ cells can give them the potential to conceive their genetic progeny. However, no biological or clinical parameters were predictive of mature or immature germ cell retrieval. WHAT IS KNOWN ALREADY: KS is the commonest sex chromosome disorder observed in azoospermic infertile males. Testicular sperm extraction success decreases with age and after testosterone therapy. Arguably, spermatozoa should be retrieved from KS males at the onset of puberty and before testosterone therapy to increase the chance of success. STUDY DESIGN, SIZE, DURATION: A retrospective study was performed in eight KS adolescents, aged between 15 and 17 years, who were referred for counseling about their future fertility to the center CECOS (Centre d'Etude et de Conservation des Oeufs et du Sperme humain) at Rouen University Hospital between October 2008 and December 2011. PARTICIPANTS/MATERIALS, SETTING, METHODS: The patients were first seen with their parents and then separately. It was proposed to them that they should provide a semen sample, if this was azoospermic, two other semen samples spaced by 3 months were collected. If azoospermia was confirmed, a bilateral testicular biopsy was proposed for sperm retrieval and testicular tissue preservation. Each adolescent met the psychologist before undergoing testicular biopsy. Paraffin-embedded testicular tissue was evaluated after staining with hematoxylin-eosin and saffron and immunostaining using vimentin, anti-Müllerian hormone, androgen receptor and MAGE-A4 antibodies. Sertoli cell maturity, germ cell identification and lamina propria alteration were assessed on seminiferous tubules. MAIN RESULTS AND THE ROLE OF CHANCE: KS adolescents were not deeply concerned about their future fertility and only became involved in the process of fertility preservation after at least three medical consultations. The parents agreed immediately that fertility preservation should be attempted. Seven non-mosaic XXY adolescents presented with azoospermia and one XXY/XY adolescent had oligozoospermia. Increased plasma levels of FSH and LH as well as bilateral testicular hypotrophy were observed in all patients. The XXY/XY adolescent banked four semen samples before testosterone replacement therapy. Two patients refused testicular biopsy. Five patients accepted a bilateral testicular biopsy. Spermatozoa were retrieved in one patient, elongated spermatids and spermatocytes I in a second patient. LIMITATIONS, REASONS FOR CAUTION: The number of patients enrolled in our study was low because the diagnosis of KS is only rarely made before or at the onset of puberty. Most XXY males are diagnosed in adulthood within the context of male infertility. WIDER IMPLICATIONS OF THE FINDINGS: Spermatozoa can be retrieved in semen sample and in testicular tissue of adolescent Klinefelter patients. Furthermore, the testis may also harbor spermatogonia and incompletely differentiated germ cells. However, the physician should discuss with the patient and his parents over a period of several months before collecting a semen sample and performing bilateral testicular biopsy. Fertility preservation might best be proposed to adolescent Klinefelter patients just after the onset of puberty when it is possible to collect a semen sample and when the patient is able to consider alternative options to achieve fatherhood and also to accept the failure of spermatozoa or immature germ cell retrieval.

Complex chromosomal rearrangement and intracytoplasmic sperm injection: a case report.

Complex chromosomal rearrangements (CCRs) are rare events in human pathology and are usually considered to induce severe reproductive impairment by disturbing the meiotic process and producing unbalanced gametes responsible for high reproductive risk. One-third of all CCRs are familial and tend to implicate fewer breakpoints and fewer chromosomes than de novo cases. CCRs are rarely transmitted through spermatogenesis and are primarily ascertained by male infertility. We report a familial balanced CCR, with seven breakpoints involving three chromosomes, which was detected prenatally in a female fetus conceived after intracytoplasmic sperm injection (ICSI) in a couple initially thought to be a carrier of a paternal reciprocal translocation involving two chromosomal breakpoints. Fluorescent in-situ hybridization (FISH) was used to elucidate the complexity of this CCR. The karyotype of the female CCR carrier was balanced and determined as 46,XX.ish t(1;4)(q42;q32)(WCP1+, D1Z5+, WCP4+, D1S3738-, D4S2930+; WCP4+, D4Z1+, WCP1+, D4S2930-, D1S3738+), ins(1;11)(q41;q23q24)(WCP1+,WCP11+, D11S2071-, MLL+; WCP11+, D11S2071+, WCP1-, MLL-), ins(4;11)(q23;q14q23)(WCP4+,WCP11+; WCP11+,WCP4-). The same balanced CCR was confirmed in her oligozoospermic father. We report, to our knowledge, the first case of ICSI performed in an infertile male with CCR, resulting in a balanced CCR carrier female with a normal clinical follow-up at 4 years of age. This particular case stresses the point of the relevance and feasibility of ICSI procedure in cases of balanced CCRs.