Trisomy 13 or 18 (mosaicism) in first trimester cytotrophoblast cells: false-positive results in 11 out of 51 cases

Objective: The finding of full or mosaic trisomy 13 or IS in first trimester chorionic villus sampling (CVS) may be a false-positive result. This report provides incidence and outcome information that may be helpful in counselling individual patients and in choosing adequate follow-up. Study design: From a series of 6820 CVS cases, we retrospectively collected data on all patients (n = 51) with full (n = 30) or mosaic (n = 5) trisomy 18, and full (n = 13) or mosaic (n = 3) trisomy 13 in cytotrophoblast cells. Results: Five false-positives were seen in patients with full trisomy 18 and three in the mosaic cases. One false-positive result was observed in full trisomy 13 and two false-positives in cases of mosaicism. No false-negative results were reported. Conclusion: The diagnosis of trisomy 13 or 18 in cytotrophoblasts should be confirmed in other tissues, unless fetal abnormalities are seen at ultrasound. In case of mosaicism, follow-up amniocentesis is advised. 2002 Elsevier Science Ireland Ltd. All rights reserve

Referral for genetic counselling during pregnancy: limited alertness and awareness about genetic risk factors among GPs

Background. In many countries, GPs play a key role in the referral to other medical specialists. Referral for reproductive genetic counselling during a pregnancy of women with a genetic risk factor already present before pregnancy has many disadvantages. Nevertheless, some 10-20% of the counsellees who attend a Department of Clinical Genetics for the first time are pregnant. Objectives. We aimed to explore the role of the GP in referring women for genetic counselling during, instead of before a pregnancy. Method. The GPs of 100 pregnant women who received genetic counselling were invited to participate in the study and asked to complete a questionnaire. The topics were: initiation and discussion of aspects of referral to the Department of Clinical Genetics; reasons for the referral during, instead of before a pregnancy; knowledge of genetic counselling; attitudes towards genetic counselling before a pregnancy; and attitudes towards abortion. Results. To our surprise, 29% of the GPs indicated that they had not been involved in the referral to the Department of Clinical Genetics at all. Furthermore, the referral was initiated by the patient herself in most cases (40%) and by the GPs in 31% of the cases. Of the GPs who were involved in the referral, most of them (79%) talked to their patients to different extents about what to expect from their visit to the Department of Clinical Genetics; however, potential choices after an adverse outcome at prenatal diagnosis were discussed less often (60%). The main reason for referring the patient during, instead of before her pregnancy was because the GP was unaware of a potential risk factor before pregnancy (71%) and, consequently, never had a chance to talk about a referral before (71%). Other reasons for referral during pregnancy mentioned by the GPs were reassuring the patient about the health of her unborn child (32%) and the wish of the patient to be referred during pregnancy (31%). GPs considered their knowledge of clinical genetics to be limited (mean score 5, on a scale from 0 to 10). The majority of the GPs were in favour of genetic counselling taking place before, instead of during pregnancy, and they had no great objections to abortion. Conclusions. During pregnancy, the gatekeeper function of the GP in the referral for genetic counselling is undermined. Limited alertness and awareness among GPs about genetic risk factors in their patients played a major role in this undermined function and in the less appropriate timing of referral. Neither insufficient knowledge nor barriers to acceptance explained this lack of alertness and awareness. We advocate the implementation of routine family history taking in general practic

Mutations in the human BOULE gene are not a major cause of impaired spermatogenesis

Mutation screening of the BOULE gene in 156 men with azoospermia or severe oligozoospermia revealed no relevant mutations; thus, mutations in BOULE can be eliminated as a major cause of impaired spemiatogenesis. (C)2005 by American Society for Reproductive Medicin

Long-term follow-up of infants after transcervical chorionic villus sampling and after amniocentesis to compare congenital abnormalities and health status

Objectives Next to procedure-related fetal loss, other adverse effects of invasive prenatal diagnosis have been reported: limb defects after chorionic villus simpling (CVS) or early amniocentesis and respiratory distress after amniocentesis (AC). Because minor abnormalities may, be overlooked in routine Follow-up, We obtained long-term follow-up data after CVS and AC. Methods 1509 women with a singleton pregnancy who had transcervical CVS were matched by age and season of conception with 1509 women with singleton pregnancies who had AC. All Procedures Were performed during 1985-1991 for advanced maternal age >35 years. Data regarding congenital malformations (classified according Eurocat), neonatal and paediatric morbidity and complications of motor development. speech, hearing and Visual function were obtained by questionnaire in 1993-1995. Results Short-term outcome was known in all but ten infants. Questionnaires with a Structured design were mailed to all women With a surviving infant (n = 2810): 86.7% responded. No difference was detected between infants after CVS compared with infants after AC regarding congenital malformations (7.2%) versus 6.3%), neonatal morbidity (15.1% versus 15.9%), paediatric morbidity with clinical treatment (7.7% versus 6.3%) or outpatient treatment only (43.9% versus 40.3%) and evident function disturbance (2.0% versus 2.0%) or doubtful function disturbance (6.3% versus 6.8%). The number of infants with physical growth <10th centile for Dutch infants was equal (10.1%). Sub-analysis for limb abnormalities or respiratory complications did not demonstrate differences between infants after CVS and AC. Only 10% of all congenital malformations were already known through routine post-partum follow-up. Conclusion All extensive long-term survey could not demonstrate differences of health status between infants after prenatal diagnosis by transcervical CVS and AC. Copyright (C) 2002 John Wiley Sons, Lt

Partial DAZ deletions in a family with five infertile brothers

Objective: To study the genetic cause of infertility in a family with five infertile brothers. Design: Case report. Setting: Center for reproductive medicine at a university medical center. Patient(s): Five brothers presenting with primary infertility due to severely impaired spermatogenesis; also, their parents and two other paternally related family members. Intervention(s): Fluorescence in situ hybridization and sequence family variant analysis was performed in leukocyte DNA to determine the number of deleted in azoospermia (DAZ) genes. Linkage analysis was performed for X chromosome inheritance, and mitochondrial DNA (mtDNA) was screened for mutations. Main Outcome Measure(s): DAZ gene copy number, X chromosome linkage, and mtDNA sequence. Result(s): With conventional polymerase chain reaction (PCR) analysis, no deletions of the AZFc region were found, but with fluorescence in situ hybridization and sequence family variant analysis, only two DAZ genes instead of four were detected in all individuals tested. The five brothers did not share an identical X chromosomal locus, and no mutations were found in the mtDNA of the index patient. Conclusion(s): A reduced copy number of the DAZ genes is found in five infertile brothers with severely impaired spermatogenesis, as well as in their normospermic father and in two other fertile paternally related family members. This illustrates that the phenotype associated with a reduced copy number of the DAZ genes can be extremely variabl

Reproductive outcome after chromosome analysis in couples with two or more miscarriages: case-control study

Objective To compare reproductive outcomes in couples carrying a structural chromosome abnormality and non-carrier couples referred for chromosome analysis after two or more miscarriages. Design Case-control study. Setting Six centres for clinical genetics in the Netherlands. Participants 278 carrier couples and 427 non-carrier couples referred for chromosome analysis between 1992 and 2000 after two or more miscarriages before 20 weeks of gestation. Couples were followed up for at least 24 months after chromosome analysis. Main outcome measures The birth of at least one healthy child, at least one more miscarriage, and viable offspring with unbalanced chromosomal abnormalities after parental chromosome analysis. Results Mean follow-up after chromosome analysis was 5.8 years. 120 of 247 (49%) carrier couples had one or more miscarriage after chromosome analysis compared with 122 of 409 (30%) non-carrier couples (difference 19%, 95% confidence interval 11% to 26%; P < 0.01). The percentage of couples with at least one healthy child was not significantly different in carrier couples (83%) and non-carrier couples (84%) (difference -1%, - 7% to 5%). Among 550 pregnancies in carrier couples, two viable unbalanced chromosome abnormalities were detected at prenatal diagnosis (0.4%) and the fetuses aborted and two children with an unbalanced karyotype were born (0.4%). Conclusions Couples whose carrier status was ascertained after two or more miscarriages have a low risk of viable offspring with unbalanced chromosomal abnormalities. Their chances of having a healthy child are as high as non-carrier couples, despite a higher risk of miscarriage

Reduced copy number of DAZ genes in subfertile and infertile men

Objective(s): To determine the copy number and identity of the DAZ genes on the Y chromosomes of infertile patients. Design: Prospective study. Setting: University medical center. Patient(s): One hundred and thirty-nine patients with male factor infertility. Intervention(s): The separate genes were detected by polymerase chain reaction (PCR) digestion assays of sequence family variants in leukocyte DNA and by fluorescence in situ hybridization of interphase nuclei and chromatin fibers. Main Outcome Measure(s): Number of DAZ genes present. Result(s): One hundred twenty-nine patients had four genes, 6 patients had two genes, and 4 patients had none. Three patients had a deletion of the two proximal DAZ genes, and three were missing both distal genes. Semen analysis showed a less severe phenotype in patients with only two DAZ genes compared with patients missing all four genes. Conclusion(s): In six patients, two different partial deletions were found that were not detected by PCR with conventional markers. One patient with an AZFb deletion appeared to also have a partial AZFc deletion that was not detected by routine PCR. Phenotypic differences between patients with different deletions suggest a dose effect of the DAZ genes. (Fertil Steril(R) 2002;77:68-75. (C) 2002 by American Society for Reproductive Medicine.

Perspectives of couples with high risk of transmitting genetic disorders

Objective: To investigate the preference for preimplantation genetic diagnosis (PGD) as an alternative to prenatal diagnosis (PND) in a large group of couples representing a wide array of genetic disorders. We also investigated the couple's familiarity with PGD and presented time trade-off scenarios for PGD versus PND, as PGD treatment is regularly accompanied by waiting lists. Design: Questionnaire study. Setting: Patient organizations representing genetic disorders. Patient(s): A total of 210 couples carrying genetic disorders. Main Outcome Measure(s): Preference for PGD or PND and familiarity with PGD in carrier couples. Result(s): Fifteen organizations representing 38 genetic disorders agreed to participate. Nine hundred eighty-three couples responded. In total 210 couples were in their reproductive years (women 18-40 years) and had a desire to conceive. Ninety couples (42%) had never heard of PGD. After they were informed, 127 couples (60%) wanted to have diagnostic testing (PND or PGD) performed. Ninety-four (74%) of these couples preferred testing with PGD. When no waiting list was used 102 couples (80%) preferred PGD. With a 2-year waiting list for PGD, 58 couples (46%) would opt for PGD. Conclusion(s): Many carrier couples are unaware of the existence of PGD. When informed, most couples prefer PGD more than PND. The preference for PGD decreases with longer waiting lists. (Fertil Steril (R) 2010;94:1239-43. (C) 2010 by American Society for Reproductive Medicine.

The use of spermHALO-FISH to determine DAZ gene copy number

The AZFc region of the human Y chromosome is frequently deleted in men with spermatogenic failure and contains many multicopy genes. The best-characterized gene family within this region is the Deleted in AZoospermia (DAZ) gene family, which is present in four nearly identical copies. Recent reports claim deletions of some but not all DAZ genes. The assays used in these studies, however, are unable to provide conclusive evidence on the number of DAZ genes. In this study we show that with the use of highly decondensed sperm nuclei with large DNA domains (spermHALO) it is possible to determine the number of DAZ genes accurately. Using this fluorescent in-situ hybridization (FISH) technique, which has both high resolution and high range, we show that in 10 normospermic men, in which PCR digest assays indicated a deletion of one or more DAZ genes, all four DAZ genes were present. Also we confirmed previous findings of a deletion of two DAZ genes in two men and identified a man with six DAZ genes. Our results indicate that spermHALO-FISH allows an accurate determination of DAZ gene copy number, while PCR digest assays do not. Therefore, confirmation of positive results from PCR digest assays with spermHALO-FISH is essential. Furthermore, the spermHALO-FISH technique should prove useful as a genetic mapping technique in other regions of the Y chromosome and similar repetitive regions throughout the genom