Indications for prenatal diagnosis and pregnancy outcomes of Turner syndrome with different karyotypes in 205 cases / 中华围产医学杂志

Objective:To investigate the indications for prenatal diagnosis and pregnancy outcomes of fetal Turner syndrome (TS) with different karyotypes.Methods:Clinical data of TS cases diagnosed by fetal karyotyping in the Prenatal Diagnostic Center of Guangzhou Women and Children′s Medical Center from January 1, 2010, to June 30, 2021, were analyzed retrospectively. According to the karyotyping results, these cases were divided into two groups: monosomy X (45,X) and non-monosomy X groups (including karyotypes of mosaic monosomy X, isochromosome X, X deletion, X rearrangement, pseudodicentric X, and mosaicism with Y or Y deletion). Chi-square test was used to compare the detection rate, indications for prenatal diagnosis, and pregnancy outcomes of the two groups, and the Bonferroni test was conducted for further pairwise comparisons between the subgroups. The Chi-square test (or Fisher's exact test) was used to compare the abnormal ultrasound signs. Mann-Whitney U test was used to compare the nuchal translucency (NT) thickness of the two groups. Results:(1) Invasive prenatal diagnosis was performed on 27 981 pregnancies, and 205 (0.73%) of them were diagnosed with TS, including 135 cases of monosomy X and 70 cases of non-monosomy X (44 with numerical sex chromosome abnormalities, and 26 with structural sex chromosome abnormalities). (2) Out of the 205 pregnancies, 164 (80.0%) had one indication for prenatal diagnosis, and 41 (20.0%) had multiple indications. The detection rate of fetal ultrasonographic abnormalities [85.2% (115/135)] in monosomy X cases was significantly higher than that of three other indications [positive serological screening for Down's syndrome: 67.3% (35/52); positive non-invasive prenatal testing (NIPT) for sex chromosome abnormality: 60.0% (15/25); and other indications (advanced maternal age, adverse pregnancy history and thalassemia genes carried by both parents): 5.2% (7/135); all P<0.05], and also higher than the figure in non-monosomy X cases [25.7% (18/70), χ 2=71.55, P<0.001]. In non-monosomy X cases, the detection rates of TS among cases with high-risk results from serological screening for Down's syndrome and NIPT for sex chromosome abnormality [54.7% (29/53) and 68.3% (28/41)] were higher than those of the other two indications [fetal ultrasonographic abnormalities: 25.7% (18/70), other indications: 14.3% (10/70); all P<0.05]. (3) Of the 133 pregnancies with fetal ultrasonographic abnormalities as the indication, 65 (48.9%) had one abnormal ultrasound sign, and 68 (51.1%) had multiple signs. Among the 95 cases with ultrasound abnormalities in the first trimester and 38 cases in the second or third trimester, the incidence of cystic hygroma and hydrops was significantly higher in monosomy X cases than in non-monosomy X cases [in the first trimester: 71.8% (61/85) vs 1/10, 34.1% (29/85) vs 0/10; in the second or third trimester: 73.3% (22/30) vs 0/8, 50.0% (15/30) vs 0/8; Fisher's exact test, all P<0.05]. NT thickness in monosomy X cases was greater than that of non-monosomy X cases [7.5 mm (1.0-17.4 mm) vs 1.7 mm (0.8-9.5 mm), Z=－5.25, P<0.001]. (4) Among the 72 pregnancies with indications other than ultrasound abnormalities, 68 underwent Down's syndrome screening and 61 underwent NIPT. The detection rates among the cases with positive results in Down's syndrome screening, NIPT for a sex chromosome abnormality, and other indications (advanced maternal age, adverse pregnancy history, and thalassemia genes carried by both parents) were 54.4% (37/68), 59.0% (36/61) and 22.2% (16/72), respectively ( χ 2=22.40, P<0.001). The detection rates of the cases with high-risk results from Down's syndrome screening and NIPT for sex chromosome abnormality were higher than that of the cases with other indications ( χ 2=18.77 and 15.40, both P<0.001). Of the 72 pregnancies, 19 (26.4%) were monosomy X and 53 (73.6%) were non-monosomy X, including 42 (58.3%) with chromosomal mosaicism. (5) Among the 205 cases of TS, 185 were successfully followed up (123 were monosomy X and 62 were non-monosomy X). There was one live birth in monosomy X cases (0.8%, 1/123) and 17 in non-monosomy X cases (27.4%, 17/62), and the difference was statistically significant ( χ2=33.22, P<0.001). Sixty-three TS cases with normal ultrasound findings were followed up (18 were monosomy X and 45 were non-monosomy X). In these cases, all 18 pregnancies with monosomy X and 32 (71.1%, 32/45) with non-monosomy X were terminated and the other 13 (28.9%, 13/45) cases of non-monosomy X were delivered. Of the 18 live births, one (non-monosomy X) was delivered at 36 weeks of gestation and the rest were born at term. Eleven cases of them were followed up. The height of one child with monosomy X was lower than the average height of children of the same age and sex by more than 2 standard deviations (－2 SD). The height of 10 children with non-monosomy X were between－1 SD and +3 SD among the children of the same age and gender. The mental and motor development were good in the 11 cases, and no other structural abnormalities were observed. The remaining seven cases refused to be followed up. Conclusions:Ultrasonographic abnormalities are the main indications of fetal TS with monosomy X, while positive Down's syndrome screening and positive NIPT for sex chromosome abnormality are indicators of non-monosomy X. The termination rate for pregnancies with monosomy X is higher than that for non-monosomy X.

Prenatal diagnosis and pregnancy outcome of increased nuchal translucency with or without nuchal cystic hygroma in fetuses during first trimester / 中华围产医学杂志

Objective:To compare the prenatal diagnosis and pregnancy outcome of increased nuchal translucency (NT) with or without nuchal cystic hygroma (CH) in fetuses with first-trimester NT ≥5 mm.Methods:Data from 131 fetuses with NT ≥5 mm who received invasive prenatal diagnosis at Guangzhou Women and Children's Medical Center from July 2017 to December 2020 were retrospectively collected and analyzed. Those with a septum in the cyst were grouped as NT with CH group ( n=57), and those without as increased NT without CH group ( n=74). Genetic test results, incidence of structural malformations, survival rate after birth were compared using Chi-square test or Fisher's exact test and non-parametric test. Results:There was no significant difference in the incidence of fetal genetic abnormalities[67.6%(50/74) vs 61.4%(35/57), χ 2=0.54, P=0.464], ultrasonic structural malformations [21.6%(16/74) vs 33.3%(19/57), χ 2=2.26, P=0.133], or in the survival rate (12/14 vs 3/8, P=0.053) between increased NT without CH group and NT with CH group. Conclusions:For increased NT with or without CH, although the two groups had different spectrum of disease, they had a high incidence of chromosomal abnormalities and structural malformations, and both groups had a certain healthy survival rate after birth.

Prenatal diagnosis and clinical outcomes of 297 fetuses with conotruncal defects / 中华妇产科杂志

Objective:To analyze the prenatal diagnosis results and pregnancy outcomes of conotruncal defects (CTD) fetuses, and to explore the correlation between the CTD and chromosome diseases.Methods:A total of 297 cases of invasive prenatal diagnosis and chromosome analysis were collected at the Prenatal Diagnosis Center of Guangzhou Women and Children′s Medical Center due to CTD from January 1st, 2011 to December 31th, 2019. According to ultrasonic diagnosis, CTD fetuses were divided into 6 subtypes: tetralogy of Fallot (109 cases), pulmonary atresia (30 cases), transposition of the great arteries (77 cases), double outlet right ventricle (53 cases), truncus arteriosus (14 cases) and interrupted aortic arch (14 cases). According to whether they were combined with intracardiac or extracardiac abnormalities, they were divided into simple group (134 cases), combined with other intracardiac abnormalities group (86 cases), combined with extracardiac abnormalities group (20 cases), combined with intracardiac and extracardiac abnormalities group (37 cases) and only combined with ultrasound soft marker group (20 cases), the last 4 groups were referred as non-simple types. The chromosome test results and pregnancy outcomes of each type and group were analyzed retrospectively.Results:Among the 297 CTD fetuses, the chromosome abnormality rate was 17.5% (52/297). There were 21 cases of abnormal chromosome number, 28 cases of pathogenetic copy number variantions and 3 cases of mosaics. All the 19 cases of micropathogenic fragments smaller than 5 Mb were detected by chromosomal microarray analysis (CMA). Among all the subtypes of CTD, the chromosomal abnormality rate of truncus arteriosus was the highest, at 7/14; while the rate of transposition of the great arteries was the lowest, at 5.2% (4/77). There were significant differences in the rate of chromosomal abnormalities between simple and non-simple types [10.4% (14/134) vs 23.3% (38/163); χ2 =8.428, P=0.004]. In each group, the chromosomal abnormality rate was the highest in the combined with intracardiac and extracardiac abnormalities group, at 37.8% (14/37), and the lowest in the simple group, at 10.4% (14/134). There was no significant difference in the rate of chromosomal abnormalities in all subtypes of simple group (all P>0.05). Among 112 cases of live birth, 1 case was 22q11.2 microdeletion syndrome, 5 cases of postnatal clinical diagnosis and prenatal ultrasound diagnosis were not completely consistent, 5 cases died after birth. Conclusions:The incidence of chromosomal abnormalities is high in fetuses with CTD. CTD fetuses with concurrent extrapardiac malformations are more likely to incorporate chromosomal abnormalities. CMA technology could be used as a first-line genetic detection method for CTD. After excluding chromosomal abnormalities, most of the children with CTD have good prognosis.

Prenatal genetic diagnosis of the fetuses with isolated corpus callosum abnormality / 中华妇产科杂志

Objective:To explore the application value of chromosome karyotype analysis, chromosomal microarray analysis (CMA) and whole exome sequencing (WES) in prenatal diagnosis of isolated corpus callosum abnormality (CCA) fetus.Methods:Fetuses diagnosed with isolated CCA by ultrasound and MRI and receiving invasive prenatal diagnosis in Guangzhou Women and Children′s Medical Center and Qingyuan People′s Hospital from January 2010 to April 2021 were selected. Karyotype analysis and/or CMA [or copy number variation sequencing (CNV-seq)] were performed on all fetal samples, and WES was performed on fetal samples and their parents whose karyotype analysis and/or CMA (or CNV-seq) results were not abnormal.Results:Among 65 fetuses with isolated CCA, 38 cases underwent karyotype analysis, and 3 cases were detected with abnormal karyotypes, with a detection rate of 8% (3/38). A total of 49 fetuses with isolated CCA underwent CMA (or CNV-seq) detection, and 6 cases of pathogenic CNV were detected, the detection rate was 12% (6/49). Among them, the karyotype analysis results were abnormal, and the detection rate of further CMA detection was 1/1. The karyotype results were normal, and the detection rate of further CMA (or CNV-seq) detection was 14% (3/21). The detection rate of CMA as the first-line detection technique was 7% (2/27). A total of 25 fetuses with isolated CCA with negative results of karyotyping and/or CMA were tested by WES, and 9 cases (36%, 9/25) were detected with pathogenic genes. The gradient genetic diagnosis of chromosomal karyotyping, CMA and WES resulted in a definite genetic diagnosis of 26% (17/65) of isolated CCA fetuses.Conclusions:Prenatal genetic diagnosis of isolated CCA fetuses is of great clinical significance. The detection rate of CMA is higher than that of traditional karyotyping. CMA detection could be used as a first-line detection technique for fetuses with isolated CCA. WES could increase the pathogenicity detection rate of fetuses with isolated CCA when karyotype analysis and/or CMA test results are negative.

Consistency between quantitative fluorescent-polymerase chain reaction and karyotyping in prenatal diagnosis / 中华围产医学杂志

Objective:To analyze the consistency between karyotyping and quantitative fluorescent- polymerase chain reaction (QF-PCR) in prenatal diagnosis.Methods:This study retrospectively analyzed the clinical data of 10 967 patients undergoing karyotyping and QF-PCR for prenatal diagnosis in Guangzhou Women and Children's Hospital from January 2010 to December 2017. The failure rate, results, and diagnosis of common chromosomal disorders of the two methods were compared. The sensitivity and specificity of QF-PCR in detecting chromosomal mosaicism were evaluated using the receiver operative characteristic (ROC) curve.Results:(1) The failure rates of karyotyping and QF-PCR were 0.99% (109/10 967) and 0.10% (11/10 967), respectively. (2) The karyotypes of 9 960 out of the 10 858 successfully cultured samples were normal, and 99.89% (9 949/9 960) results were consistent between the two methods. The other 898 cases included 694 (77.28%) with common chromosomal abnormalities (trisomy 21, 18 and 13 and sex chromosomal abnormality) and 204 (22.72%) with other chromosomal abnormalities. The consistency between the two methods in detecting common chromosomal abnormalities was 95.68% (664/694). (3) The consistency in the detection of trisomy 21, 18 and 13 and sex chromosomal abnormality between karyotyping and QF-PCR were 99.74% (382/383), 100.00% (125/125), 100.00% (33/33) and 81.05% (124/153). However, the common chromosomal mosaicism was only noted for 44.44% (24/54). (4) Among cases with a mosaic ratio over 18.5%, the sensitivity and specificity of QF-PCR were 0.958 (95% CI: 0.789-0.999) and 0.600 (95% CI: 0.406-0.773) with the area under the ROC curve (AUC) of 0.811 (95% CI: 0.696-0.926, P<0.001). (5) Thirty cases with negative QF-PCR results but positive mosaic chromosomal aberrations were followed up. Ten (33.3%) pregnant women terminated their pregnancies, and two (6.7%) were lost to follow-up. The other 18 cases delivered healthy neonates that all survived after birth. Conclusions:In prenatal diagnosis, QF-PCR and karyotyping were highly consistent in the detection of trisomy 21, 13, and 18, but have significant discordance in the diagnosis of sex chromosomal abnormality.

Clinical and genetic analysis of three pediatric patients with 15q24 microdeletion syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for three patients with development delay and to correlate their clinical phenotypes with genetic findings.@*METHODS@#The karyotypes of the probands and their parents were analyzed by conventional G-banding. Chromosomal microarray analysis (CMA) was used to detect microdeletion and microduplication.@*RESULTS@#No kartotypic abnormality was detected in the patients and their parents. CMA analysis identified a de novo 3.10 Mb deletion on chromosome 15q24.1q24.2 in case 1, a de novo 3.14 Mb deletion at 15q24.1q24.2 in case 2, and a 3.13 Mb deletion at 15q24.1q24.2 in case 3. All deletions have encompassed the CPLX3,SEMA7A and SIN3A genes.@*CONCLUSION@#The three patients were diagnosed with 15q24 microdeletion syndrome. CPLX3,SEMA7A and SIN3A may be the key genes responsible for this syndrome.

Chorionic villus cell culture and karyotype analysis in 1983 cases of spontaneous miscarriage / 中华妇产科杂志

Objective To investigate the relationship between spontaneous miscarriage and embryonic chromosome abnormalities,and to evaluate the clinical application of karyotype analysis by chorionic villus cell culture. Methods The chorionic villus karyotype of 1983 cases of miscarriage from January 2010 to July 2016 in Guangzhou Women and Children′ s Mecical Center were analyzed retrospectively. The miscarried chorionic villi were obtained by curettage under sterilized condition. The chromosome specimens were prepared after chorionic villus cell culture. Karyotype analysis was performed by G-banding technique. Results In the 1983 samples, successful karyotype analysis was performed in 1770 cases, with the successful rate of 89.98%. Chromosomal abnormalities were found in 1038 cases (58.64%,1038/1770). Chromosomal structural abnormalities were found in 37 cases. The numeral abnormalities were more common than structural abnormalities, and most of the numeral abnormalities were aneupoidies. In turn, they were trisomy 16, 45,X, trisomy 22, trisomy 2, trisomy 21, trisomy 15. The most common structural abnormality was balanced translocation, including Robersonian translocation. Female embryoes accounted for 61.02%(1080/1770) miscarriages and for 57.4%(596/1770) of chromosomal abnormalities, while male embroyes acoounted for 61.02%(1080/1770),57.4%(596/1770)respectively. The proportion of female embryoes was higher than male embryoes. The median age of the patients was 30 years old(16-46 years old). As the maternal age increased, the proportion chromosomal abnormalities increased. The incidence of chromosomal abnormalities in the advanced age group (≥35 years) was 68.38%(240/351), which was significantly higher than that in the younger group (56.24% ,798/1419; χ2=17.10, P<0.01). Conclusions Embryonic chromosomal abnormalities are the most common cause of early spontaneous miscarriage. The abnormalities centralize in some karyotypes. There is certain relationship between maternal age and the incidence of miscarriage, as well as the embryonic gender. Chorionic villus cell culture and karyotype analysis are helpful in finding the cause of miscarriage and counsel the patients.

Prenatal ultrasound screening for fetal cleft lip and palate and related abnormalities / 中华围产医学杂志

Objective To evaluate the sensitivity and specificity of prenatal ultrasound for detecting fetal cleft lip and palate,and the diagnosis rate of associated congenital structural and chromosomal abnormalities.Methods Thirty one thousand two hundred and forty five singleton pregnant women accepted prenatal examination and delivered in Guangzhou Women & Children' s Medical Center from Jan.2006 to Dec.2010 were recruited in this study.All pregnant women underwent prenatal ultrasound screening during second trimester,and whose fetuses were suspected to be cleft lip and palate were suggested to accept karyotype analysis.All babies delivered received oral examination to diagnose cleft lip and palate.Results Cleft lip and palate was diagnosed in 48 cases (1.5‰,48/31 245).Among which,there were 16 cases (33.3％,16/48) of cleft lip,21 cases (43.8％,21/48) of cleft lip with cleft palate and 11 cases (22.9％,11/48) of cleft palate.Prenatal ultrasound screening suggested 18 cases of cleft lip and 14 cases were comfirmed after birth with the accuracy rate of 77.8％,3 cases were diagnosed to be cleft lip with cleft palate and one cases was misdiagnosed.Prenatal ultrasound screening suggested 18 cases of cleft lip with cleft palate in accordance with the diagnosis after birth.Thirteen cases were normal in prenatal ultrasound screening,but two were diagnosed as cleft lip and 11 were diagnosed as cleft palate after birth.The sensitivity of prenatal ultrasound screening for cleft lip and cleft lip with cleft palate was 86.5％(32/37),and the sensitivity for cleft lip and palate was 66.7％ (32/48),the false positive rate was 2.1％ (1/48).Ten cases (27.8％,10/36) of cleft lip with cleft palate were found to be complicated with other abnormalities.Nine of the 18 cases prenatally diagnosed cleft lip with cleft palate accepted karyotype analysis and 7 were abnormal.Twenty-three of 36 cases with fetal cleft lip and palate in prenatal ultrasound screening were induced.Conclusions Ultrasound screening has a high sensitivity for detection of cleft lip with or without cleft palate,but difficult to detect cleft palate.The risk of combining with chromosomal defects in cleft lip fetus is very low,but might increase once associated with cleft palate.

Quantitative fluorescent-polymerase chain reaction for rapid prenatal diagnosis of common aneuploidies / 中华围产医学杂志

Objective To evaluate the clinical value of quantitative fluorescent polymerase chain reaction (QF-PCR) in rapid prenatal diagnosis of aneuploidies. Methods Twenty-two short tandem repeats (STR) and AMXY located on chromosome 13,18,21,X and Y were used as markers to examine 1740 samples from high risk pregnant women in Down syndrome screening and advanced maternal age(≥35 yrs) by QF-PCR.Samples were also tested by karyotype analysis and the results of the two methods were compared. Results Karyotype analysis and QF-PCR results were successfully obtained from 1690 samples. All QF-PCR reports were obtained within 48 hours after sample collection.For 1639 samples,normal results were obtained by both karyotype analysis and QF-PCR.Among 51 samples that were found abnormal by karyotype analysis,41 were abnormal in QF-PCR.The rapid tests found all numerical abnormalities involving chromosome 21,18,13,X and Y in prenatal diagnosis,including trisomy 21 (n =30),trisomy 18 (n =6),45,XO (n =1 ),47,XYY (n=1),47,XXX (n=1),69,XXX (n=1) and mosaic 47,XXY[94]/46,XX[6] (n=1)(47,XXY in QF-PCR).No false positive results were found.The results obtained by QF-PCR were consistent with those of cytogenetic studies in 99.4％ of the samples (1680/1690).Only ten cases of mosain and structural abnormality could not be found (0.6％,10/1690) by QF-PCR. Conclusions Rapid QF-PCR test might diagnose all aneuploidies involving chromosome 21,18,13,X and Y.It could provide rapid and accurate diagnosis for 99.4％ pregnant women with positive Down syndrome screening and advanced maternal age.

Application of array-based comparative genomic hybridization in precise diagnosis of unbalanced chromosome aberration / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To evaluate the method of array-based comparative genomic hybridization (array-CGH) in identifying unbalanced chromosome aberrations.</p><p><b>METHODS</b>Four cases that could not be diagnosed by conventional cytogenetic technique were selected to undergo array-CGH analysis. DNA samples were extracted and hybridized with the Affymetrix SNP 6.0 arrays using Human Mapping SNP6.0 assay kit following the manufacturer's standard protocol. The data were analyzed by two professional software packages, GCOS and Genotyping Console.</p><p><b>RESULTS</b>By using array-CGH technique, all the four cases were diagnosed precisely through identifying two duplications and two complex derivative chromosomes.</p><p><b>CONCLUSION</b>Array-CGH is an effective method for whole-genome identification of unbalanced chromosomal aberrations with high sensitivity and specificity. It has a great value to investigate the correlations between genotype and phenotype in clinical service, especially in prenatal diagnosis.</p>

Application of spectral karyotyping in diagnosis and prenatal diagnosis of the marker chromosome / 中华妇产科杂志

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 wag 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 vahable tool to diagnose the marker chromosome with rapidness,direct-viewing and sensitiveness.It can be used to assess the prognosis and the pregnancy outcome.