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Background/aim: Although cutting edge procedures such as cell-free fetal DNA isolation from maternal blood are now available, invasive prenatal tests are still being used extensively for prenatal diagnosis. The study aims to evaluate the demographic data, indications, and cytogenetic results of 9297 results of patients who underwent prenatal invasive testing for genetic analysis that were referred for the last 20 years in a University Medical Genetics Center., Materials and Methods: The records of 8363 amniocenteses, 626 chorionic villus, and 308 cordocenteses samples were retrospectively evaluated and analyzed regarding referral reasons, indications and their cytogenetic results. The total numbers and the percentages of each group were recorded; Chi-square and logistic regression analyses were performed to give the statistical likelihood of different events., Results: The number of referrals decreased significantly after 2009. Risk of having trisomy 21 as well as trisomy 13 and 18 significantly increased in parallel with advanced maternal age. When the 21–25 age group was compared to the older age groups in terms of having a trisomy 21 pregnancy, the risk doubled in the 36–40, 5 times higher in 41–45 and 10-fold in 46–50 age groups. No significant linear correlation between maternal serum screening test results and trisomy 21 was found, however the difference between the pregnancies whom cut-off value above and below 1/250 in maternal serum screening test were significant., Conclusion: These data have provided useful information on the frequency of referrals to the reference genetics department, and the feasibility of genetic services. By reviewing the indications and their corresponding results, we can offer invaluable insights that will be useful in genetic counseling and also in the development of more effective genetic strategies., (This work is licensed under a Creative Commons Attribution 4.0 International License.)

The recent publication of a study into the contribution of embryo chromosomal abnormalities in recurrent pregnancy loss (RPL) affords the opportunity to revisit the hypothesis that women with an aneuploid pregnancy loss have a better chance of a successful pregnancy next time than women with a chromosomally normal loss. A previous miscarriage with an abnormal karyotype (unrelated to a parental chromosome rearrangement) should not be viewed as a marker of an increased likelihood of aneuploidy in a subsequent pregnancy; it is (counterintuitively) likely to be indicative of a reduced risk of clinical miscarriage (with a higher proportion of aneuploid products) and an excellent chance for the live birth of the next pregnancy. Each couple should be treated on their own merits and with appropriate investigations performed where indicated; caution should be advised regarding offering preimplantation genetic testing for aneuploidy (PGT-A).

Background: We analyzed the cytogenetic characteristics of a representative population of young adults with de novo acute myéloblastic leukemia (AML) treated in a single center institution., Methods: Patients with de novo AML included were aged between 20 and 60 years. Cytogenetic analysis was done at diagnosis. Twenty cells were analyzed, although examination of lower numbers of metaphases was also acceptable if an abnormal clone was detected., Findings: From 1/1/04 to 31/12/2014, among 1315 adult patients, 1055 (80%) patients were aged between 20 and 60 years. Karyotype was done in 927 (88%) patients and cytogenetic analysis failed in 32 cases (3·4%). Clonal abnormalities were observed in 520 (58%) patients. 175 (19·5%) were classified in the favorable group, 609 were in the intermediate group and 111 (12·5%) were in the adverse group. The most frequent chromosomal abnormality observed was t(8;21) in 112 (12·5%). Thirty three (3·7%) patients had t(15;17) and 30 (3·3%) had inv16, trisomy 8 was found in 47 (5·2%), 11q23 rearrangements in 32 (3·6%), 67 (7·4%) had a complex karyotype, -5/del(5q) and -7/del(7q) were seen in, respectively, 11(1%) and 27 (3%). Monosomy occurred in 115 (13%) patients, 70 (8%) responded to the definition of monosomal karyotypes., Interpretation: This is the largest study done in Morocco, Africa and Middle East. Epidemiological studies involving different ethnic populations and geographic regions of the world should help unfold the true nature of environmental and genetic interplay in the development of AML. Our cytogenetic profile reveals some particularities when compared to other populations; it does not seem to be similar neither to eastern or western countries., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: Infertility is estimated to affect 15% of couples, having chromosome abnormalities an important role in its etiology. The main objective of this work was to access the reproductive success of ART in infertile couples with chromosomal abnormalities comparing to a control group with normal karyotype., Methods: A 7-year retrospective karyotype analysis of infertile couples was done. Data regarding type of infertility, couples' ages, ART performed, and their reproductive success were obtained. Adjusted odds ratio (OR) were used to estimate magnitude of association between the reproductive success and the different groups., Results: We found a prevalence of 7.83% of chromosome abnormalities in our population (233 couples out of 2989). Chromosomal anomalies were found in 82 men (34.75%) and 154 women (65.25%), with low-grade mosaicism being the most prevalent (50.85%), followed by autosomal translocations (17.37%) and sex chromosomes abnormalities (13.56%). Only 2359 couples were treated with ART. There was a non-significant lower reproductive success rate in the cases (OR = 0.899, p = 0.530) with IVF providing the higher success rate. In general, female carriers of chromosome anomalies had a higher success rate, although not significant., Conclusion: Although the differences regarding success rate between groups were not found statistically significant, we still advocate that cytogenetic analysis should be performed routinely in all infertile couples namely before ART. This might help deciding the best treatment options including Preimplantation Genetic Testing for aneuploidies or structural rearrangements and minimize the risk of transmission of anomalies to the offspring.

Mutations of ASXL1 are early events in acute myeloid leukemia (AML) leukemogenesis and have been associated with unfavorable prognosis. In this study, we investigated the type and frequency of ASXL1 mutations in a large cohort of patients with de novo or secondary AML (s-AML) and looked for correlations with cytogenetic findings and disease features. ASXL1 mutations were associated with older age, s-AML and higher peripheral leukocytosis. We observed more frequent co-occurrence of ASXL1 mutations with trisomy 8 and chromosome 11 aberrations but a negative correlation with myelodysplastic syndromes (MDS)-related cytogenetic abnormalities, especially -5/del(5q) and -7/del(7q). ASXL1 mutations were also found in other genetically defined AML subgroups such as those with t(9;22), inv(3)/t(3;3), t(8;21) or t(15;17); however, none of our inv(16) cases carried ASXL1 mutations. We detected two previously unreported ASXL1 mutations, p.IIe593Val and p.Cys688Tyr. Our findings suggest that ASXL1 mutations tend to cluster with specific clinical and cytogenetic profiles of AML patients.

Purpose: The aim of the study was to assess cytogenetic and embryoscopic characteristics in subsequent miscarriages of spontaneous pregnancy losses (SPL) and recurrent pregnancy losses (RPL)., Methods: A retrospective cohort of 75 women was affected by repeated pregnancy loss. Of those, 34 had SPL, 24 primary RPL, and 17 secondary RPL. Ploidy status and morphology was analyzed by transcervical embryoscopic examination of the embryo and cytogenetic analysis of the chorionic villi in subsequent miscarriages., Results: Similar rates of recurrent ploidy status were observed between first and second miscarriage in SPL and RPL (82.4% recurrent ploidy status in SPL, p > 0.999; 73% recurrent ploidy status in RPL, p = 0.227). No difference was found regarding recurrent abnormal morphology between SPL and RPL (p = 0.092). However, secondary RPL resulted significantly more often in recurrent abnormal morphology compared to primary RPL (p = 0.004)., Conclusions: High rates of recurrent normal/abnormal karyotypes were observed in all groups with a majority of embryos presenting with recurrent abnormal morphology. Secondary RPL presented significantly more often with recurrent abnormal morphology compared to primary RPL. These findings offer prognostic information for the affected patient and might impact treatment choice.

Background: Many different causes of malformations have been established. The surveillance of a consecutive population of births, including stillbirths and elective terminations of pregnancy because of fetal anomalies, can identify each infant with malformations and determine the frequency of the apparent etiologies. This report is a sequel to the first such analysis in the first 10 years of this Active Malformations Surveillance Program (Nelson and Holmes, )., Methods: The presence of malformations was determined among 289,365 births over 41 years (1972-2012) at the Brigham and Women's Hospital in Boston. The abnormalities were identified from the review of the examination findings of the pediatricians and consultants and diagnostic testing for the live-born infants and the autopsies of the fetuses in elective terminations and stillbirths., Results: A total of 7020 (2.4%) infants and fetuses with one or more malformations were identified with these apparent etiologies in 26.6%: Mendelian disorders, including infants with postaxial polydactyly, type B; chromosome abnormalities; vascular disruption; complications of monozygous twinning; and environmental factors. The malformations of unknown etiology were a much larger group., Conclusion: While several causes of malformations have been identified, many remain unexplained. Combining the ascertainment in a future surveillance programs with genome sequencing and chromosome microarray analysis will increase significantly the number of malformations attributed to genetic mechanisms. Birth Defects Research 110:87-91, 2018.© 2018 Wiley Periodicals, Inc., (© 2018 Wiley Periodicals, Inc.)

Few studies have examined the value of cytogenetic studies with flow cytometry (FC) in lymph node/extranodal tissue biopsies with suspected lymphoma. To evaluate this, G-banded karyotyping and/or fluorescence in situ hybridization (FISH) with FC immunophenotyping were performed on 185 lymph node or extranodal tissue biopsy specimens with suspected lymphoma. Complete cytogenetic analysis of lymph node/extranodal tissue was successful in 174 cases (94.1%) and 57.5% demonstrated chromosomal abnormalities. In 116 malignant lymphoma cases, 83.8% showed abnormalities. In 74 B cell lymphomas (B-NHL), abnormalities were more frequent in lymph node/extranodal tissues than in bone marrow by conventional cytogenetics (CC, 97.2 vs 26.1%), FISH (70.6 vs 17.6%), and FC (98.6 vs 28.4%). Three B-NHL diagnoses were confirmed by re-biopsy of lymph nodes due to the presence of abnormalities in the first biopsy, but no evidence of malignancy in pathological, FC, or IgH/TCR gene rearrangement analyses. In 29 T cell lymphomas (T-NHL), abnormalities were more frequent in lymph nodes than in bone marrow by CC (67.9 vs 21.4%) and FC (75.9 vs 27.6%) analyses. As expected, in 13 Hodgkin lymphoma cases, abnormalities were more frequent in lymph nodes than bone marrow by CC (41.7 vs 16.7%) and FC (30.8 vs 7.7%) analyses. In 56 reactive lymphoid hyperplasias (RLH), 7.1% had conventional clonal cytogenetic abnormalities. Two of these patients died of disease progression and two had their pathological diagnosis revised after the second review. These findings indicate that cytogenetic analysis combined with FC in lymph node/extranodal tissue biopsies can provide critical information in the auxiliary diagnosis of lymphoma.

Despite years of research, miscarriage, particularly when recurrent, continues to pose a medical challenge. An embryo chromosomal error is responsible for 50-60% of recurrent cases; however, up to 30-50% remains an enigma. Successful pregnancy involves different maternal physiologic changes and certain complex interactions between the fetus and the mother by cytokines, angiogenic mediators and hormones. To date, research lines have focused on genetic and epigenetic polymorphisms related mainly to immune response and inflammatory mediators, and have yielded a significant relationship between recurrent miscarriage and immune mechanisms. Thus, unknown causes of miscarriage could be due to an immune imbalance induced by T-helper Th1/Th2/Th17 cytokines and regulatory T cells. Furthermore, these genes and mediators have long been suspected of being blood markers for the clinical diagnosis and management of miscarriage; however, more evidence is required for them to be included in medical practice and obstetric guidelines., (Copyright © 2017. Published by Elsevier Ltd.)

In order to contribute to the knowledge of type and frequency of chromosome abnormalities in early pregnancy losses, we analyzed the cytogenetic results from a large series of first trimester miscarriages, using a diagnostic approach with a high success rate and no maternal contamination. A total of 1,119 consecutive chorionic villi samples were obtained before evacuation, and karyotypes were prepared after short-term culture (STC). In 603 samples, a long-term culture (LTC) was also performed. The overall and individual frequencies of the different types of chromosome abnormalities were established, including placental mosaicisms, and their relationship with maternal age and gestational weeks was assessed. An abnormal karyotype was detected in 70.3% of the samples. Single autosomal trisomy was the most frequent abnormality (64.6% of the abnormal cases), followed by triploidy (13.1%) and monosomy X (10.4%). Chromosome rearrangements were found in 5.2%, combined abnormalities in 8.9%, and placental mosaicism in 3.5% of the cases with STC and LTC performed. Individual trisomies behaved differently with respect to maternal age and intrauterine survival. Due to the combination of STC and LTC, our study offers reliable information on the incidence and type of chromosome abnormalities and placental mosaicism in miscarriages and contributes to define the cytogenetic implication in their etiology., (© 2017 S. Karger AG, Basel.)

Both B-cell and T-cell acute lymphoblastic leukemia (ALL) exhibit recurrent cytogenetic alterations, many with prognostic implications. This chapter overviews the major recurrent categories of cytogenetic abnormalities associated with ALL, with an emphasis on the detection and characterization of these cases by G-band and FISH analyses.

This study aimed to investigate whether occupational and environmental exposures, lifestyle, family, and medical history are associated with chronic lymphocytic leukemia (CLL) risk and its chromosomal abnormalities. The study included 138 CLL cases and 141 age- and sex-matched controls. Information data were collected through in-person interviews from cases and controls. Cytogenetic analysis was performed on CLL bone marrow cells. Positive associations were found between CLL and cancer family history, smoking, pneumonia, and exposure to petroleum, metals, pesticides/chemical fertilizers, detergents, and medical radiation. Chromosome deletions of 11q and 13q were more frequent in patients exposed to pesticides and rubber, respectively. This study investigated for the first time specific risk factors in relation to CLL aberrations and presented positive correlations. Moreover, it indicates the possible involvement of specific occupational and lifestyle risk factors in the onset of CLL.

Individuals affected by the classic chromosome deletion syndromes which were first identified at the beginning of the genetic age, are now positioned to benefit from genomic advances. This issue highlights five of these conditions (4p-, 5p-, 11q-, 18p-, and 18q-). It focuses on the increased in understanding of the molecular underpinnings and envisions how these can be transformed into effective treatments. While it is scientifically exciting to see the phenotypic manifestations of hemizygosity being increasingly understood at the molecular and cellular level, it is even more amazing to consider that we are now on the road to making chromosome abnormalities treatable conditions., (© 2015 Wiley Periodicals, Inc.)

Ventriculomegaly (VM) is a marker of aneuploidy and warrants a detailed examination of fetal anatomy. Chromosomal abnormalities worsen the fetal and neonatal prognosis significantly and karyotyping of fetuses is critically important when accompanying anomalies are detected. Here, we report the genetic results of 140 fetuses with isolated and non-isolated VM detected during a second trimester ultrasound examination followed by invasive in utero diagnostic procedures for karyotyping. VM was diagnosed in seven (5%) fetuses with abnormal karyotype and the chromosomal abnormality incidence was higher in severe VM (6.8%) than mild (4.2%). Higher chromosomal abnormality rates were detected when VM was isolated (8.6%), rather than associated with any anomaly (3.8%). These results suggest that karyotype analysis should be offered to all patients with any degree of VM, regardless of its association with structural anomalies.

Background: Trisomy 18 (Edwards' syndrome, T18) is the second most common trisomy in man. We describe 118 children with regular T18 who were ascertained clinically and cytogenetically in the Kuwait Medical Genetics Centre during 1980-1997., Methods: Ascertainment of T18 cases was performed shortly after birth. Chromosomal studies were carried out in addition to other relevant investigations. To investigate the factors associated with T18, a case-control study was carried out with 131 normal healthy newborns. Studied factors included maternal and paternal age, birth order, abortion, associated malformation, and survival. Multiple logistic regression analysis was used to adjust for confounding between variables., Results: There was a preponderance of females among T18 cases (female:male ratio 2.1:1). The majority of T18 cases (53%) died before the second week of life. The most common associated anomalies were: congenital heart (38.1%) and gastrointestinal (25.4%). Multiplicity of malformations was also observed. Significant seasonal variation in T18 cases was detected with a peak in spring. Of the 118 T18 cases, 59 were delivered during 1994-1997 (average overall T18 birth prevalence rate 8.95 per 10 000 live births [95% CI: 6.66-11.23]). Concerning maternal age, 30.5% of the T18 cases' mothers were > or =35 years compared to 10.7% in the control group. The difference was statistically significant, P = 0.002. Logistic regression analysis showed that maternal age >30 years was a significant risk factor for T18, after adjusting for confounding with paternal age. Paternal age and abortion were not found to be significant risk factors., Conclusion: Trisomy 18 birth prevalence rate is high in Kuwait with advanced maternal age as a significant risk factor.

Objective: Our purpose was to assess the family planning decisions made by women found to be carrying fetuses with chromosome abnormalities or neural tube defects., Study Design: We studied the family planning decisions of 132 women carrying fetuses with chromosome abnormalities (n = 91) or neural tube defects (n = 41) with regard to prenatal diagnosis, pregnancy management decision, patient's gravidity, and maternal and gestational age., Results: Twenty women (17 carrying fetuses with chromosome abnormalities and 3 with fetal neural tube defects) elected permanent sterilization after completion of the affected pregnancy. Only maternal age and fetal chromosome abnormalities were associated with a decision to obtain permanent sterilization., Conclusions: Most women carrying fetuses with chromosome abnormalities or neural tube defects will not choose permanent sterilization after completion of the pregnancy. Delaying such decisions until resolution of grief and depression is now facilitated by the availability of safe, reliable, and relatively long-term reversible contraceptive agents.

Induced abortion data provided an estimate of 4.7% numerical chromosome anomalies for women with a clinically recognized pregnancy at the end of the 7th week after the last menstrual period (LMP). This frequency requires that 51.9% of spontaneous abortions occurring after the 7th week should be chromosomally abnormal if the frequency of numerical chromosome anomalies at term (live and stillbirths combined) is 0.53%. Cytogenetic data from surveys of spontaneous abortion suggested a lower incidence of 39.7%. However, this figure is likely to be an underestimate because chromosome anomalies are almost certainly over-represented among the many early abortuses which lack embryonic tissue and hence are not karyotyped. The frequency of numerical chromosome anomalies at conception, arising from meiotic errors, was estimated from sperm karyotype data combined with information on the relative frequencies of maternal and paternal errors in the aetiology of trisomies. This provided a minimum estimate of 20%.

Gossypol acetic acid, a male anti-fertility drug, was evaluated for its effects on cell multiplication, chromosomes, scheduled and unscheduled DNA synthesis, and the surface ultrastructure in cultured murine erythroleukemia cells (clone 6A11A). Gossypol treatments inhibited cell multiplication at 10 and 20 micrograms/ml concentrations and this inhibitory effect increased with elevated dosage and prolonged treatment. Gossypol significantly depressed the mitotic index but did not alter chromosome numbers or increase the frequency of chromosomal structural abnormalities. Cell fraction techniques revealed that gossypol induced a negative effect on cellular DNA synthesis at concentrations as low as 3.3 micrograms/ml after 24 hr of treatment. The number of cells undergoing DNA synthesis decreased with increasing dosages and durations of drug exposure. An unscheduled DNA synthesis assay (UDS) found gossypol to be an active UDS-inducing agent at certain dose levels and treatment times, as measured by increase in net nuclear gain and percentage of UDS cells (ANOVA, Bonferroni test, P less than 0.05). A scanning electron microscope study revealed that 10 micrograms/ml treatment with gossypol caused changes in mouse erythroleukemia cell surface ultrastructure characterized by general balding and the appearance of holes, often after 48 hr of treatment.

Seventy-five selective terminations, based on abnormal laboratory findings at first-trimester CVS, were performed in 1581 consecutive pregnancies. In all cases a (semi-) direct method of cytogenetic analysis was used. The 75 abortions were analysed in number of ways. Confirmatory studies showed that three cases had to be considered as false-positive findings, and in one other case the results were inconclusive. Based on literature data, it was estimated that 41 of the 75 pregnancies would have resulted in seriously handicapped children, surviving beyond the age of 1 year, if no termination of pregnancy had taken place. Negative side-effects of the procedure include: spontaneous abortion of chromosomally normal fetuses due to the CVS procedure itself and the need for a number of secondary amniocenteses (5.1%). The advantage of DNA diagnosis in X-linked diseases is illustrated by comparing the CVS results with a previously published amniocentesis study.

In a recent study of chromosome breakage frequencies in 36 primary fibroblast cell strains derived from skin from 10 phenotypically normal women, we observed seven different clones of cells having consistent chromosomal abnormalities. Five of the stem lines were noted in cultures from "control" women and two in fibroblasts from women taking oral contraceptives. We observed aneuploid clones as well as stem lines bearing structural abnormalities (e.g., translocation, inversions). The various aberrant clones were found in cultures ranging in age from 41 to 144 days and comprised varying percentages of the cell populations ranging from 0.8% to virtually 100%. The possible evolution in culture of clones of cells having aberrant karyotypes should be considered in interpreting findings from fibroblast cultures initiated for clinical evaluation.

Three new cases of low chiasma frequency in infertile men are described. In the first case, all cells showed abnormal diakineses; in the second, 20% of the diakineses were desynaptic, while the remaining 80% were normal; in the third, all diakineses were desynaptic and showed chromosome fragmentation. The possible mechanisms leading to asynapsis, desynapsis or precocious chiasma terminalization are discussed.

Chromosomal abnormalities were studied in 33,551 abortions and births to women whose contraceptive histories had been recorded at their first antenatal visit in 1975-1977. Chromosome examinations were performed exclusively on clinical grounds. There were 45 de novo abnormalities detected (1.34/1,000); three of them were detected at amniocentesis. Trisomy 21 was observed in 27 cases (0.80/1,000), trisomy 18 in nine (0.27), other trisomies in three (0.09), and translocations or deletions in five (0.15). One case of triploidy and six cases of inherited abnormalities were detected. There were no significant racial variations. No increase in risk for chromosomal abnormalities was found among women who had used oral contraceptives prior to becoming pregnant or among women who experienced oral contraceptive breakthrough pregnancies. Two cases of trisomy 18 were observed among the 814 deliveries following oral contraceptive breakthrough conceptions (2.46/1,000), two cases of trisomy 21 occurred in 338 births following failures of rhythm contraception (5.92/1,000), and no cases of trisomy 21 or 18 among the 1,569 women using spermicides at the time of conception.

A survey of the chromosome constitution in 500 induced abortions (5-12 menstrual weeks) was undertaken over a period of 1 1/2 years. There were 34 cases (6.8%) of gross chromosome anomalies: 2 cases of trisomy A; 5 of trisomy C (including XXX and XXY); 1 of mosaic trisomy C; 4 of trisomy D; 2 of trisomy E; 2 of trisomy G; 1 of double trisomy E and G; 1 of XYY; 4 of monosmy C (including XO); 2 of mosaic monosomy C; 1 of mosaicism of ring D chromosome; 1 of extra small metacentric chromosome; 3 of triploidy (including triploidy with double trisomy C and G); and 5 of tetraploidy and its mosaicism. An increased risk for the occurrence of trisomic anomalies was found with advancing age of the mothers. In contrast, the production of monosomies was not age-related. Trisomies were the most common type of anomalies and were found almost at random, regardless of the characteristics of chromosomes. Neither satellited nor small chromosomes were predominantly involved in the formation of chromosome anomalies.

A general review of reports on the chromosomal effects of oral contraceptive has been undertaken, and it is quite apparent that there is a scarcity of literature on these very important investigations. Also, those that have been undertaken, cannot be properly assessed on account of, one supposes, subjects' background and lack of numbers, differences in techniques and, above all, the small number of metaphases analyzed. Apart from the report by Mills and colleagues [16], none of the reports mentioned exogenous agents to which the subjects might have been exposed, especially in cases where there has been an increased frequency of chromosomal aberrations. All these considerations must be taken into account for, as yet, the reports are too conflicting to 'indict' the oral contraceptive as having chromosome-breaking properties.

Human peripheral blood lymphocytes were cultured in diffusion chamber in mice after short-term administration of gossypol acetate. The induced chromosomal aberrations of human target cells indiffusion chamber were used as indices of DNA damage. The results showed that the mean frequency of chromosomal aberration of the human lymphocytes in Gossypol-treated mice was slightly higher than that in the control group, but the difference between them was not statistically significant (p 0.05).

The responsibility of demographic isolation for the high incidence of genetic disorders among the population of the Saguenay region of Quebec, Canada, is explored. The authors reject the view that "a few family founders are the ancestors of most of the current population....Actually, between 1838 and 1911, more than 28,000 immigrants (representing one third of the number of births) settled in Saguenay, a major fact that has to be taken into account if one sets out to explain the genetic structure of this population, particularly if one considers that most of these immigrants came from the same region and were grouped in kin-related families." (SUMMARY IN ENG AND SPA), (excerpt)

In order to evaluate the cytogenetic findings previously obtained on induced abortions in women exposed to 2,3,7,8 tetrachlorodibenzo-p-Dioxim (TCDD) after the Seveso accident, chromosome analyses were carried out on a comparable control sample. The frequencies of aberrant cells, the relative proportions of individual types of chromosome aberration, the average number of lesions per damaged cell, and the frequencies of polyploids do not differ significantly in maternal blood and placenta in the two samples. A highly significant increase in the frequencies of aberrant cells and in the average number of aberrations per damaged cell was found in the fetal tissues in the group of exposed pregnancies. A noticeable feature of the data on the frequencies of cells with aberrations is the marked variability among individuals within tissues and within samples. On the basis of these results, the authors point to the need to continue cytogenetic investigations on interrupted pregnancies in TCDD-exposed and nonexposed women.

The chromosomes of 3080 products of conception, consisting primarily of newborn infants and medically induced abortions, were examined. These were from 3 major groups of women, those who had used oral contraceptives (primarily the combination types), those who had used nonhormonal contraceptives, and a control group of those who had not used any contraceptives. In the newborn study population, the chromosome abnormality rate was 5.4 per 1000 infants (when cases of proven hereditary involvement are excluded the figure drops to 3.6 per 1000), and in the entire induced-abortion study series it was 7.3 per 1000. These rates are very similar to those obtained in other surveys. The rate of chromosomally abnormal conceptuses increases with increasing maternal age in both the newborn and induced-abortion groups. No statistically significant relationships were found between the observed or age-adjusted rates of chromosome abnormalities and contraceptive history (P greater than .10 in all cases). The findings make it clear that the use of oral contraceptives has no large effect on the risk of having a chromosomally abnormal child although the possibility of a small increase or decrease in this risk, of at most about 10 per 1000, cannot be ruled out because of the small number of abnormalities found.

An inmate of a hospital for the mentally retarded was found during a cytogenetic screening programme to have karyotype 46,XY,inv(19)(p13q13)mat. Clinical, cytogenetic and family findings are presented and it is concluded that the chromosomes abnormality was probably not the cause of the patient's retardation. The problem of genetic counseling of inversion carriers is examined in some detail and estimates of risk are given.

A chromosomally abnormal child with psychomotor retardation and multiple anomalies, including agenesis of the corpus callosum and cleft palate, was born following artificial insemination by donor. Chromosomal and conventional markers were used to ascertain paternity. Various banding techniques were employed to identify the origin of the extra chromosomal material as most likely a duplication-deficiency of the short arm of chromosome No. 8.

A study has been made of the chromosome numbers and characteristics of leucocytes cultured from mothers (a total of 77) who had taken one or more types of oral contraceptive, and their babies (108), and compared with similar numbers of control subjects. When the total cytogenetic results from test and control mothers were compared, no significant differences in frequency or type of chromosome abnormalities was observed. However, with certain types of oral contraceptive, minor differences in the numbers of chromosome abnormalities were found between test and control groups and the significance of these findings are discussed. The only significant abnormalities observed in the babies from mothers taking oral contraceptives were slight increases in the numbers who had cells with less than 46 chromosomes and who exhibited chromosomal gaps. The number of abnormal cells was significantly higher in babies born to mothers who had been taking norethynodrel (Conovid) (4.6% abnormal cells in test babies; 2.0% in controls).

The significance of oral contraceptives in causing chromosome aberrations in the fetus was studied in 246 non-selected spontaneous abortuses using Q-banding technique. No significant difference in the frequency of abnormal karyotypes or in the sex ratio was found between 124 abortuses of women who had taken oral contraceptives in comparison with 122 abortuses of women who had never used oral contraceptives. The study did, however, show that women who had used oral contraceptives were significantly younger than women who had not used these pills. In addition, the gestational age of the chromosomally abnormal abortuses was on the average 6 days longer in the group of women who had used oral contraceptives than in the group who had not. The difference was significant only with regard to the karyotype 45,X.

To determine whether exposure to synthetic hormones resulted in increased chromosome damage in cells other than lymphocytes, we evaluated series of lymphocyte and fibroblast cultures from five control women and five women taking oral contraceptives (OC). The results of this study showed: (1) no difference in chromosome breakages between lymphocytes and fibroblasts; (2) no differences in breakages in replicate fibroblast cultures exposed to fetal calf serum, autologous serum, homologous serum, or homologous serum from OC users; (3) no difference in breakage between lymphocyte and fibroblast cultures from OC users, compared with lymphocyte and fibroblast cultures from control women; and (4) no increase in the frequency of cytogenetically aberrant stem-lines in fibroblast cultures from women taking OC. These findings suggest that synthetic hormones do not cause increased chromosome breakages in fibroblasts from women taking OC.

Data from 1,550 consecutive pregnancies after first-trimester prenatal diagnosis by transcervical chorionic villus sampling (TC-CVS) are presented. The sampling efficacy was 97.8 per cent; the mean amount of collected villus tissue was 23 mg (range 5-100 mg). There were 97 affected fetuses, mainly (73.2 per cent) with a chromosomal abnormality or a male karyotype in carriers of X-linked disease. Pregnancy termination in these and four other women for social reasons resulted in 1449 continuing pregnancies. In these pregnancies, the fetal loss rate up to 28 weeks of gestation was 5.1 per cent with the highest loss rate (3.9 per cent) before 16 weeks. When relating this fetal loss rate to maternal age, this was 6.1 per cent in the advanced maternal age group (greater than or equal to 36 years) against 3.1 per cent in the younger age group. In 1,376 pregnancies continuing beyond 28 weeks, the perinatal mortality rate was 1.1 per cent; the percentage of non-genetic congenital anomalies was 0.9 per cent. The reproductive pattern of women at high genetic risk after CVS followed by pregnancy termination was evaluated. Within 12 months after the first CVS followed by pregnancy termination, 70 per cent of women again requested CVS in a subsequent pregnancy.