Chromosomal polymorphisms are independently associated with multinucleated embryo formation.

PURPOSE: The purpose of this study is to explore the factors associated with embryo multinucleation, particularly focused on the influence of parental chromosomal polymorphisms in embryo multinucleation. METHODS: This is a retrospective case-control study involving 1260 infertile couples undergoing their first IVF/ICSI cycles. Couples were screened for abnormalities in their karyotype and were evaluated for blastomere persistence of multinucleation. Demographic characteristics, stimulation protocol, and pregnant outcomes were analyzed using logistic regression analysis. RESULTS: The level of basal FSH was lower in the multinucleated embryos group (5.37 vs 5.72 IU/L). The Multinucleated embryos group received less gonadotropins (1788.5 vs 1891.3 IU), and the level of LH on day of HCG triggering was lower (1.09 vs 1.30 IU/L). More oocytes were recovered in the multinucleated embryos group (11.51 vs 9.23). Chromosomal polymorphisms were seen in at least 1 out of 163 (12.9%) couples. Multivariate logistic regression analysis revealed that chromosomal polymorphisms were independently associated with an increase in the occurrence risk of multinucleated embryos (OR = 1.61, 95% CI, 1.06-2.44) in the first IVF/ICSI cycle. The miscarriage rate in the multinucleated embryos group was 10% higher than that of the control group. CONCLUSIONS: Chromosomal polymorphisms were independently associated with multinucleation embryo formation. A higher LH level on the day of HCG triggering was associated with a decreased chance of multinucleation.

The prevalence of non-detectable chromosomal abnormalities by QF-PCR in amniocentesis for certain referral indications: experience at a mainland Chinese hospital.

PURPOSE: To study the prevalence of non-detectable chromosomal abnormalities by quantitative fluorescent polymerase chain reaction (QF-PCR) in a Chinese population referred for amniocentesis. METHODS: The karyotype results were reviewed in 8,466 amniotic fluid cultures performed for positive fetal Down syndrome screening or advanced maternal age between January 2002 and June 2012. The karyotype results were classified as detectable or not detectable by QF-PCR, using the assumption that all tests were conducted by this rapid molecular method. RESULTS: Of the 8,466 karyotypes obtained, 211 abnormal karyotypes were found (2.5%). Out of these, 168 cases of common aneuploidies were identified by QF-PCR, and 43 cases of chromosomal abnormalities were missed. The 43 cases missed by QF-PCR included 31 cases predicted to confer no increased risk and 12 with a potential clinical significance. When QF-PCR shows a normal result, the overall residual risk is 0.1% for any clinically significant chromosomal abnormality. CONCLUSIONS: A normal QF-PCR result predicts a very low residual risk for patients who are referred solely for an increased risk of a common trisomy.

[Dandy-walker syndrome and microdeletions on chromosome 7].

OBJECTIVE: To investigate genetic etiology of Dandy-Walker syndrome with array-based comparative genomic hybridization (array-CGH). METHODS: Eight fetuses with Dandy-Walker malformations but normal karyotypes by conventional cytogenetic technique were selected. DNA samples were extracted and hybridized with Affymetrix cytogenetic 2.7 M arrays by following the manufacturer's standard protocol. The data were analyzed by special software packages. RESULTS: By using array-CGH technique, common deletions and duplication on chromosome 7p21.3 were identified in three cases, within which were central nervous system disease associated genes NDUFA4 and PHF14. CONCLUSION: Copy number variations (CNVs) of chromosome 7p21.3 region are associated with Dandy-Walker malformations which may be due to haploinsufficiency or overexpression of NDUFA4 and PHF14 genes.

[Application of fluorescence in situ hybridization to prenatal diagnosis of aneuploidy in 110 uncultured amniotic fluid samples].

OBJECTIVE: To optimize the prenatal diagnosis platform by using domestically made fluorescence in situ hybridization(FISH) kit and to explore the clinical application of FISH to rapid prenatal diagnosis of a wide range of chromosomal abnormalities. METHODS: Amniotic fluid samples from 110 pregnant women were studied with the rapid prenatal diagnosis method of FISH and the conventional cell culture method of karyotyping, the results from both methods were compared. RESULTS: Four cases of trisomy 21, 1 case of trisomy 18, 58 cases of 46, XX, and 47 cases of 46, XY were detected by FISH in the 110 amniotic fluid samples. It is concordant with the results from conventional karyotype analysis. The concordance rate is 100%. CONCLUSION: Domestically made FISH kit can be used to rapidly and accurately detect the most common chromosome aneuploidies by using less sample volume while the price is relatively low. FISH can be a reliable and rapid prenatal diagnostic tool as an adjunct to classical cytogenetic study. It can be used for rapid and accurate prenatal diagnosis of women with high risk of maternal serum screening.

[Application of spectral karyotyping in diagnosis and prenatal diagnosis of the marker chromosome].

OBJECTIVE: To determine the value of spectral karyotyping(SKY) in identification of the marker chromosome. METHODS: Selected six cases that could not be identified in clinic were studied, using samples of peripheral blood from four cases, and samples of amonic fluid and fetal cord blood for prenatal diagnosis in two cases were investigated. All cases were analyzed with the routine SKY method, and the results with the SKY View software. The SKY results were identified by using fluorescence in situ hybridization (FISH). And C-banding technique was used to help diagnose the heterochromatin. RESULTS: SKY was successfully performed on all of 6 cases. The origin of all marker chromosomes was identified by SKY. Except case No. 4, the others were confirmed by FISH. It helped determine the pregnancy outcome in two cases of prenatal diagnosis: one case of genetic marker chromosome continued the pregnancy, and another case of de novo marker chromosome was terminated of the pregnancy. CONCLUSION: SKY may be a valuable tool to diagnose the marker chromosome with rapidness,direct-viewing and sensitiveness. It can be used to assess the prognosis and the pregnancy outcome.

[Application of spectral karyotyping in diagnosis of complex chromosome aberration].

OBJECTIVE: To determine the value of spectral karyotyping (SKY) to identify the complex chromosome aberration. METHODS: Four cases were selected that can not be identified by standard cytogenetic techniques. The chromosome specimens were detected by the routine SKY method, and the results were analyzed by the SKY View software. RESULTS: By using SKY a case of complex chromosome rearrangements and two cases of chromosome duplication were identified. However it could not identify the chromosome inversion and the breakpoint of chromosome aberration. CONCLUSION: SKY may be a valuable tool in identification of complex chromosome translocation, rearrangement, minute aberration and unknown derivative chromosomes. Though SKY can not replace the standard cytogenetic techniques, but it will be the benefit supplementary.

[Polymorphisms analysis of short tandem repeat loci D21S1433, D21S1442, D21S1444, D21S2051 in Guangdong Han nationality in China].

OBJECTIVE: To investigate the polymorphic distribution of short tandem repeat (STR) sequences D21S1433, D21S1442, D21S1444, D21S2051 in Guangdong Han nationality in China. METHODS: Using quantitative fluorescens PCR technology, the authors analyzed 200 unrelated samples to acknowledge the allele frequency, heterozygosity and other genetic information. RESULTS: D21S1433, D21S1442, D21S1444, D21S2051 were tested in 200 samples, which were tested to be statistical according to Hardy-Weinberg equilibrium (P> 0.05), 9, 10, 9 and 5 alleles were detected separately in each STRs. The heterozygosity of each STR was 0.818, 0.820, 0.770, and 0.261. The polymorphic information content > 0.7 in D21S1433, D21S1442, D21S1444, while D21S2051 owned only 0.247 polymorphic information. CONCLUSION: D21S1433, D21S1442, D21S1444 are found to have high heterozygosity and polymorphic information content, and they could provide useful markers for genetic purposes, while D21S2051 is not informative in Guangdong Han nationality in China.

Application of real-time fluorescence quantitative PCR to rapid molecular detection of Down's syndrome.

OBJECTIVE: To develop a rapid and reliable technique for the detection of Down's syndrome. METHODS: The peripheral blood samples were collected from twenty-five Down's syndrome patients and fifty normal individuals. Four polymorphic loci on chromosomes 21, 1, 19 were amplified by real-time fluorescence quantitative PCR, and then four pairs of deltaCt values were analytically compared between the two groups. RESULTS: The deltaCt values of Down's syndrome patients were significantly lower than those of normal individuals, and the reference ranges for clinical application were primarily established. The difference between the two groups was highly significant (P < 0.001), and the reference ranges between the two groups were not overlapped. Real-time quantitative PCR technique can effectively differentiates Down's syndrome samples from the normal fetuses; furthermore, the results were consistent with those of the karyotype analysis. CONCLUSION: Real-time quantitative PCR is a fast and reliable method that may provide a new approach for rapid detection of Down's syndrome.

[Studies on safety of cordocentesis guided by transabdominal ultrasound for prenatal diagnosis].

OBJECTIVE: To assess the safety and efficacy of diagnostic cordocentesis during pregnancy. METHODS: During March 1990 to June 2003, 2403 consecutive cordocenteses were performed under transabdominal ultrasound guidance at Guangzhou Women and Children's Hospital. The results of each procedure was prospectively collected and subsequently analysed in terms of operational complications and pregnancy outcomes. RESULTS: Success rate of cordocentesis: totally 2368 procedures (98.5%) were done successfully at the first attempt, and 35(1.5%) required repeated cordocentesis, 16 of which were performed successfully at second attempt. Duration of cordocentesis: In 75.5% cases, the procedure was completed in less than 5 min, and in 93.0% cases in less than 10 min. COMPLICATIONS: Transient bleeding at puncture site was observed in 315 cases (13.1%), transient fetal bradycardia in 125 cases (5.2%), and chorioamnionitis in 2 cases (0.1%). Pregnancy outcomes: The total fetal loss rate was 0.8% (18 cases of abortions). The rate of premature birth after cordocentesis was 0.2% (4 cases). CONCLUSION: Cordocentesis during pregnancy is a useful, relatively safe, and effective procedure for prenatal diagnosis.