Placental weight in pregnancies with trisomy confined to the placenta.

OBJECTIVE: Mosaicism with trisomy confined to the placenta is present in ~1% of ongoing pregnancies at the time of chorionic villus sampling. Some studies have found reduced fetal growth in confined placental trisomy. The objective of this study was to assess placental weight and feto-placental weight ratio in pregnancies with trisomy confined to the placenta, and to correlate them with the level of trisomy in the three major placental lineages. METHODS: We conducted a retrospective study of 69 pregnancies with prenatally diagnosed mosaic trisomy in which the trisomic cells were confined to the placenta. Placental weight and feto-placental weight ratio were compared to those of matched controls, and placental weight was also analyzed for associations with the type and level of trisomy. Placental pathology was also reviewed. RESULTS: The pregnancies with mosaic trisomy were found to have lower placental weights than matched controls, but normal feto-placental weight ratios. Placental weight was not associated with the type or level of trisomic cells in the three placental lineages at term (chorionic plate, chorionic villus mesenchyme, and trophoblast). There were no pathognomonic findings on routine placental pathology of the trisomic placentas. CONCLUSION: Although placental weight was reduced (with normal feto-placental weight ratio) in pregnancies with trisomy confined to the placenta, the level of placental trisomy was not correlated with placental weight. Thus, trisomy may alter placental function rather than have a direct hypoplastic effect on placental growth. More in-depth studies beyond routine pathology are required to identify how trisomy affects placental function.

Postnatal follow-up of prenatally diagnosed trisomy 16 mosaicism.

OBJECTIVE: To determine the long-term outcome of pregnancies prenatally diagnosed with trisomy 16 and identify variables associated with the outcome. METHODS: We reviewed all published and our unpublished data from trisomy 16 pregnancies for which outcomes were available for children of greater than 1 year of age. RESULTS: Nineteen cases were diagnosed with trisomy 16 on chorionic villus sampling (CVS) and 17 cases at amniocentesis. Age at last follow-up ranges from 1 to 13 years. Among the CVS group, four out of five patients, with a birth weight and/or length below -2 SD and postnatal growth information, showed catch-up growth (80%). Among the amniotic fluid (AF) group, the birth weight was available in 13 cases. Eleven of the 13 cases had a birth weight less than -2 SD. In eight cases, the length was also below -2 SD (length data unavailable in one case). Nine out of ten cases (90%) and seven out of eight (87.5%) showed catch-up growth for weight and length, respectively. In terms of development, no cases of CVS mosaicism had global developmental delay. One child had a history of delay in speech development. Among the AF-detected cases, 4/17 cases had global developmental delay. All four children with global developmental delay had more than one major malformation compared to 6 out of 32 children in the group with normal development (p = 0.004). The finding of uniparental disomy (UPD) was not associated with developmental delay. CONCLUSIONS: The majority of prenatally diagnosed trisomy 16 mosaic cases have a good postnatal outcome. However, the finding of mosaicism on AF and the presence of major congenital anomalies are associated with an increased risk of developmental delay.

Frequency of chromosomal abnormalities in spontaneous abortions derived from intracytoplasmic sperm injection compared with those from in vitro fertilization.

No statistical difference was found for the total aneuploidy rate in the spontaneous abortions between intracytoplasmic sperm injection and IVF groups; however, differences in the distribution of chromosomal abnormalities between the two groups were seen.

Abnormal embryonic development diagnosed embryoscopically in early intrauterine deaths after in vitro fertilization: a preliminary report of 23 cases.

OBJECTIVE: To provide data about the phenotypic appearance of the embryo of early failed pregnancies after IVF. DESIGN: Clinical prospective descriptive study. SETTING: Tertiary care center. PATIENT(S): Twenty-three women who had conceived by IVF and had a missed abortion before 12 weeks of gestation. INTERVENTION(S): Embryoscopic examination of the embryo before curettage. Cytogenetic analysis of the chorionic villi by standard G-banding cytogenetic techniques or by comparative genomic hybridization in combination with flow cytometry analysis. MAIN OUTCOME MEASURE(S): Embryonic phenotype and karyotype were determined. RESULT(S): Twenty-one of 23 IVF embryos showed structural defects on embryoscopic examination. Seventeen of 23 specimens had a chromosomal abnormality. The majority were numerical aberrations such as monosomy X (2 cases). Trisomies for chromosomes 18 (one case), 16 (three cases), 15 (one case), 14 (two cases), 13 (one case), 12 (one case), 11 (one case), 10 (one case), 9 (one case), 8 (one case), and 3 (one case) were observed. A structural chromosome anomaly leading to a chromosomal trisomy was observed in one case. Aneuploidy explained the grossly abnormal embryonic development documented by embryoscopy in 15 of 21 cases. CONCLUSION(S): Aneuploidy is the major factor affecting normal embryonic development in missed abortions after IVF. Further investigation is needed to elucidate mechanisms that might prevent normal embryogenesis but evade detection by the cytogenetic techniques used in the present study.

Allogeneic bone marrow transplantation for children with acute myelocytic leukemia in first remission demonstrates a role for graft versus leukemia in the maintenance of disease-free survival.

In Children's Cancer Group (CCG) study 2891, patients who were recently diagnosed with acute myelocytic leukemia (AML) were assigned randomly to standard- or intensive-timing induction chemotherapy. Patients in first complete remission (CR1) and who had a human leukocyte antigen (HLA)-identical, related donor or a donor disparate at a single class I or II locus were nonrandomly assigned to receive a bone marrow transplant (BMT) by using oral busulfan (16 mg/kg) and cyclophosphamide (200 mg/kg). Methotrexate only was given for graft-versus-host disease (GVHD) prophylaxis. One hundred fifty patients received transplants. Grade 3 or 4 acute GVHD occurred in 9% of patients. Patients younger than 10 years had a lower incidence of grade 3 or 4 GVHD (4.6%) compared with patients 10 years or older (17.4%) (P =.044). Disease-free survival (DFS) at 6 years was 67% and 42% for recipients of intensive- and standard-timing induction therapies, respectively. Multivariate analysis showed that receiving intensive-timing induction therapy (P =.027) and having no hepatomegaly at diagnosis (P =.009) was associated with favorable DFS, and grades 3 and 4 acute GVHD were associated with inferior DFS. Multivariate analysis showed that grades 1 or 2 GVHD (P =.008) and no hepatomegaly at diagnosis (P =.014) were associated with improved relapse-free survival (RFS). Our results show that children older than 10 years are at higher risk for developing severe GVHD; acute GVHD is associated with favorable RFS.

Morphology of the 45,X embryo: an embryoscopic study.

The morphology of monosomy X in embryos was documented by means of transcervical embryoscopy prior to evacuation in 24 cases of missed abortion. The embryos ranged in size from 13 mm to 26 mm CRL and were all developed beyond the sixth week of development. The embryonic phenotype varied from nearly normal to obviously abnormal with a combination of localized external developmental defects consisting of microcephaly, facial dysplasia, and retarded limb development. A single case of encephalocele was observed. The factors responsible for the wide range of developmental defects observed in monosomy X embryos are currently unknown. Transcervical embryoscopy can serve as a central component for further genetic studies elucidating these mechanisms which are needed for reaching a further understanding of the developmental effects of specific aneuploidy in human morphogenesis.

Loss of 1p and 7p in radiation-induced meningiomas identified by comparative genomic hybridization.

Cytogenetic and molecular studies of radiation-induced meningiomas (RIM) are rare and controversial. While comparative genomic hybridization (CGH) analysis identified monosomy 22 as the predominant change in RIM, occurring in frequencies comparable to those found in spontaneous meningioma (SM), molecular genetic analysis shows infrequent loss of chromosome 22 DNA markers. We have performed CGH analysis of six additional cases of RIM and detected an unbalanced genome in five of 6 cases. Loss of 1p and 7p was identified in the majority of RIM with an abnormal karyotype (4/5 cases), whereas loss of 6q occurred in three of five cases. Only one of five RIM had monosomy for chromosome 22. Loss of 7p is not frequently reported in SM and yet it was detected in four of 5 RIM with an abnormal karyotype in our study. Molecular and cytogenetic studies of chromosome 7 copy number should be attempted on a larger number of RIM to further investigate the role of 7p loss in RIM.

Origin of amnion and implications for evaluation of the fetal genotype in cases of mosaicism.

OBJECTIVE: To investigate presence of trisomy in amniotic epithelium (uncultured amnion) and mesenchyme (cultured amnion) from mosaic cases to understand the origins of these tissues and their relationship to pregnancy outcome. METHODS: Polymerase chain reaction (PCR) of microsatellite loci was used to determine the presence of trisomy (of meiotic origin only) in amnion samples from 33 placentas previously ascertained because of a prenatal diagnosis of trisomy mosaicism that was predominantly confined to the placental tissues. RESULTS: In 16 (48%) of 33 cases, trisomy was confirmed to be present by molecular analysis of uncultured amnion. In contrast, cytogenetic analysis of cultured amnion showed trisomy in only 2 of 20 informative cases. The molecular detection of trisomy in amnion was strongly associated with poor pregnancy outcome (intrauterine growth restriction, fetal anomalies and/or intrauterine/neonatal death) even when analysis was limited to cases negative for the trisomy on amniotic fluid (N = 22, p = 0.0005). CONCLUSIONS: We infer that amniotic mesenchyme (usually diploid) derives from early embryonic mesoderm of the primitive streak and not from the hypoblast as is commonly cited. Trisomy in amniotic epithelium suggests that high numbers of abnormal cells were present in the epiblast, and this correlates with poor outcome even when the subsequently derived fetus and amniotic mesenchyme appear to carry only diploid cells.

Molecular cytogenetics in reproductive pathology.

This chapter presents the summary of two molecular cytogenetic techniques--FISH and CGH--with their applications and limitations in the studies of pregnancy loss. These molecular techniques clearly represent a significant advantage over the traditional cytogenetic technique and likely will become the predominant cytogenetic techniques in reproductive cytogenetics of the future.

Generalized abnormal embryonic development in missed abortion: embryoscopic and cytogenetic findings.

A direct view of the embryo by means of transcervical embryoscopy prior to evacuation in 154 cases of missed abortion showed general embryonic maldevelopment in 48 cases (31%). A successful cytogenetic evaluation of these growth-disorganized embryos was performed in 37. Chromosomal abnormalities were found in 26 cases (70%), with autosomal trisomies in 24 cases (92%). Trisomies involved chromosome 3 (one case), 6 (one case), 8 (two cases), 10 (one case), 12 (two cases), 14 (one case), 16 (11 cases), 20 (one case), and 22 (four cases). Most of these chromosome abnormalities represented nonviable defects, and their presence explained the minimal embryonic development observed embryoscopically. An apparently normal karyotype was observed in 11 growth-disorganized embryos whose maldevelopment was similar to that resulting from the trisomies listed above. The factors responsible for embryonic maldevelopment with a normal karyotype are presently unknown and require further study, including investigation of imprinting defects, subtelomeric abnormalities, and cryptic mosaicism.

Interphase fluorescence in situ hybridization and DNA flow cytometry analysis of medulloblastomas with a normal karyotype.

Interphase fluorescence in situ hybridization (FISH) with chromosome 3 and 17 centromeric probes and DNA flow cytometry were used for a retrospective study of nine pediatric medulloblastomas with normal karyotypes after tissue culture. The FISH analysis of medulloblastoma touch preparations showed that in seven of nine tumors, a significant proportion of nuclei had an increased number of centromeric signals for the selected chromosomes. In six of seven cases, this increase was caused by the presence of triploid and tetraploid clones as established by flow cytometry of paraffin-embedded tumors. These findings show that molecular cytogenetic analysis combined with DNA flow cytometry is necessary for all pediatric medulloblastomas diagnosed as cytogenetically normal on cultured tumor tissue.

Neural tube defects in missed abortions: embryoscopic and cytogenetic findings.

Transcervical embryoscopy, a new technique for direct visualization of the first trimester conceptus was carried out in 116 cases of missed abortion. Embryonic neural tube defects and other localized developmental defects, were diagnosed in 10 out of 99 cases in which a complete embryoscopic evaluation was possible. All eight successfully karyotyped cases had a numerical chromosomal abnormality. A ninth unkaryotyped embryo with open spina bifida showed, on embryoscopy, a malformation pattern highly suggestive of triploidy. Our embryoscopic and cytogenetic findings provide valuable information for genetic counseling in future pregnancies.