1.Clinical characteristics and genetic analysis of a case with 47, XYY Disorder of sex development due to variant of NR5A1 gene
Yanan LIU ; Jie LI ; Qiqi XU ; Ying YANG ; Linlin HE ; Honglei DUAN
Chinese Journal of Medical Genetics 2025;42(8):931-936
Objective:To investigate the clinical phenotype and genetic etiology of a patient with tall stature and primary amenorrhea presenting with 47, XYY Disorder of sex development (DSD).Methods:A female patient presenting with " tall stature and primary amenorrhea" at Nanjing Drum Tower Hospital in July 2024 was selected as the study subject. A retrospective study design was employed to collect the patient′s clinical data. Peripheral venous blood sample was collected. Following the extraction of genomic DNA, genetic testing was performed including chromosomal karyotyping analysis, copy number variation sequencing (CNV-seq), multiplex PCR for the AZF regions and sex-determining genes Y ( SRY), and whole-exome sequencing (WES). Candidate variants were validated by Sanger sequencing and classified for pathogenicity based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of Nanjing Drum Tower Hospital (Ethics No.: 2022-451-01). Results:The patient had a height of 188 cm and a body weight of 50 kg, in addition with infantile uterus, absent ovaries, and primary amenorrhea. G-banded karyotyping analysis of peripheral blood sample revealed 47, XYY. CNV-seq indicated Seq[GRCh37]Yp11.32q12×2. No deletion was detected in the AZF regions of Y chromosome, and SRY was positive. WES identified a heterozygous c. 86C>A (p.Thr29Lys) variant of the NR5A1 gene, leading to substitution of threonine with lysine at position 29 of the encoded protein. Sanger sequencing confirmed the presence of the variant. According to the ACMG guidelines, this variant was classified as variant of uncertain significance (VUS) with supporting evidence (PS3_Moderate+ PM5+ PP3+ PM2_Supporting+ PS4_Supporting). Reviewing the nearly 60 years of previously reported cases, all 7 documented 47, XYY DSD patients were assigned a female social gender and presented with abnormal gonadal and external genitalia development. Among them, 5 cases underwent SRY testing, all of which were positive. Only 1 case underwent whole-exome sequencing (WES), but no pathogenic or likely pathogenic variants were identified. Conclusion:This DSD patient presented with the clinical features of tall stature and primary amenorrhea. The NR5A1 gene variant c. 86C>A (p.Thr29Lys) probably underlay the disorder of sex development in this patient. Above finding has enriched the spectrum of pathogenic variants of the NR5A1 gene.
2.Clinical characteristics and genetic analysis of a case with 47,XYY Disorder of sex development due to variant of NR5A1 gene.
Yanan LIU ; Jie LI ; Qiqi XU ; Ying YANG ; Linlin HE ; Honglei DUAN
Chinese Journal of Medical Genetics 2025;42(8):931-936
OBJECTIVE:
To investigate the clinical phenotype and genetic etiology of a patient with tall stature and primary amenorrhea presenting with 47,XYY Disorder of sex development (DSD).
METHODS:
A female patient presenting with "tall stature and primary amenorrhea" at Nanjing Drum Tower Hospital in July 2024 was selected as the study subject. A retrospective study design was employed to collect the patient's clinical data. Peripheral venous blood sample was collected. Following the extraction of genomic DNA, genetic testing was performed including chromosomal karyotyping analysis, copy number variation sequencing (CNV-seq), multiplex PCR for the AZF regions and sex-determining genes Y (SRY), and whole-exome sequencing (WES). Candidate variants were validated by Sanger sequencing and classified for pathogenicity based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of Nanjing Drum Tower Hospital (Ethics No.: 2022-451-01).
RESULTS:
The patient had a height of 188 cm and a body weight of 50 kg, in addition with infantile uterus, absent ovaries, and primary amenorrhea. G-banded karyotyping analysis of peripheral blood sample revealed 47,XYY. CNV-seq indicated Seq[GRCh37]Yp11.32q12×2. No deletion was detected in the AZF regions of Y chromosome, and SRY was positive. WES identified a heterozygous c.86C>A (p.Thr29Lys) variant of the NR5A1 gene, leading to substitution of threonine with lysine at position 29 of the encoded protein. Sanger sequencing confirmed the presence of the variant. According to the ACMG guidelines, this variant was classified as variant of uncertain significance (VUS) with supporting evidence (PS3_Moderate+PM5+PP3+PM2_Supporting+PS4_Supporting). Reviewing the nearly 60 years of previously reported cases, all 7 documented 47,XYY DSD patients were assigned a female social gender and presented with abnormal gonadal and external genitalia development. Among them, 5 cases underwent SRY testing, all of which were positive. Only 1 case underwent whole-exome sequencing (WES), but no pathogenic or likely pathogenic variants were identified.
CONCLUSION
This DSD patient presented with the clinical features of tall stature and primary amenorrhea. The NR5A1 gene variant c.86C>A (p.Thr29Lys) probably underlay the Disorder of sex development in this patient. Above finding has enriched the spectrum of pathogenic variants of the NR5A1 gene.
Humans
;
Female
;
Steroidogenic Factor 1/genetics*
;
DNA Copy Number Variations/genetics*
;
XYY Karyotype/genetics*
;
Karyotyping
;
Retrospective Studies
;
Phenotype
;
Sex Chromosome Disorders of Sex Development/genetics*
;
Sex Chromosome Disorders
3.Efficacy of non-invasive prenatal testing of fetal free DNA in maternal peripheral blood in fetuses with increased nuchal translucency
Mengyao NI ; Xiangyu ZHU ; Wei LIU ; Leilei GU ; Peixuan CAO ; Ying YANG ; Xing WU ; Chunxiang ZHOU ; Honglei DUAN ; Jie LI
Chinese Journal of Perinatal Medicine 2025;28(2):113-118
Objective:To explore the efficacy of non-invasive prenatal testing (NIPT) of fetal free DNA in maternal peripheral blood in fetuses with increased nuchal translucency (NT).Methods:A retrospective analysis was conducted on 1 184 singleton pregnant women that underwent chromosomal microarray analysis (CMA) at Nanjing Drum Tower Hospital, Nanjing University Medical School from June 2014 to December 2022 due to fetal increased NT (≥3.0 mm). These subjects were categorized based on whether the increased NT was accompanied by other high-risk factors into isolated increased NT without advanced maternal age (further subdivided into 3.0 mm≤NT<3.5 mm, 3.5 mm≤NT<4.0 mm, and NT≥4.0 mm subgroups), isolated increased NT with advanced maternal age, increased NT with nasal bone abnormalities, increased NT with other soft markers, and increased NT with structural abnormalities groups. Assuming the sensitivity and specificity of NIPT and expanded NIPT at this center were both 100%, genomic abnormalities outside the detection range of NIPT or expanded NIPT were termed as residual risk of NIPT or expanded NIPT. Chi-square test and Bonferroni correction were used to compare the residual risks of NIPT and expanded NIPT among the three subgroups of isolated increased NT without advanced maternal age group. Results:(1) In the group of isolated increased NT without advanced maternal age: For the 3.0 mm≤NT<3.5 mm subgroup (329 cases), 19 abnormalities were detected by CMA [12 cases of chromosome aneuploidy, seven cases of pathogenic copy number variation (pCNV)], with residual risks of NIPT and expanded NIPT both at 2.1% (7/329). For the 3.5 mm≤NT<4.0 mm subgroup (173 cases), 29 abnormalities were detected by CMA (17 cases of chromosome aneuploidy, nine cases of pCNV, three cases of chromosome unbalanced translocation), with residual risks of NIPT at 8.1% (14/173) and expanded NIPT at 7.5% (13/173). For the NT≥4.0 mm subgroup (270 cases), CMA detected abnormalities in 70 cases (50 cases of chromosome aneuploidy, 16 cases of pCNV, three cases of unbalanced translocations, and one case of sex chromosome abnormality combined with pCNV). The residual risk of NIPT was 12.2% (33/270), and the residual risk of expanded NIPT was 7.0% (19/270). The residual risks of NIPT and expanded NIPT in the 3.0 mm≤NT<3.5 mm subgroup were lower than those in the 3.5 mm≤NT<4.0 mm and NT≥4.0 mm subgroups (Bonferroni correction, all P<0.017). (2) In the group of 92 cases with isolated increased NT and advanced maternal age, CMA detected abnormalities in 36 cases (29 cases of chromosome aneuploidy, five cases of pCNV, one case of trisomy 21 combined with sex chromosome abnormality, and one case of trisomy 18 combined with sex chromosome abnormality). The residual risk of NIPT was 7.6% (7/92), and that of expanded NIPT was 5.4% (5/92). (3) In the group of 49 cases with increased NT combined with nasal bone abnormalities, CMA detected abnormalities in 24 cases (23 cases of chromosome aneuploidy and one case of pCNV). The residual risks of NIPT and expanded NIPT were both 2.0% (1/49). (4) In the group of 26 cases with increased NT combined with other soft markers, CMA detected abnormalities in nine cases (six cases of chromosome aneuploidy, one case of pCNV, and two cases of chromosome unbalanced translocations). The residual risks of NIPT and expanded NIPT were both 11.5% (3/26). (5) In the group of 245 cases with increased NT combined with structural abnormalities, CMA detected abnormalities in 121 cases (107 cases of chromosome aneuploidy, seven cases of pCNV, four cases of chromosome unbalanced translocations, one case of trisomy 21 combined with trisomy 20, and two cases of trisomy 18 combined with sex chromosome abnormalities). The residual risk of NIPT was 16.7% (41/245), and that of expanded NIPT was 4.1% (10/245). Conclusions:For isolated NT≥3.5 mm or NT≥3.0 mm combined with other high-risk factors, chorionic villus sampling in early pregnancy can be recommended, advancing the timing of prenatal diagnosis from the second trimester to the first trimester. For fetuses with isolated 3.0 mm≤NT<3.5 mm, the 2.1% residual risk of chromosomal abnormalities should be fully informed during counseling, even if the risk of NIPT is low.
4.Clinical characteristics and genetic analysis of a case with 47, XYY Disorder of sex development due to variant of NR5A1 gene
Yanan LIU ; Jie LI ; Qiqi XU ; Ying YANG ; Linlin HE ; Honglei DUAN
Chinese Journal of Medical Genetics 2025;42(8):931-936
Objective:To investigate the clinical phenotype and genetic etiology of a patient with tall stature and primary amenorrhea presenting with 47, XYY Disorder of sex development (DSD).Methods:A female patient presenting with " tall stature and primary amenorrhea" at Nanjing Drum Tower Hospital in July 2024 was selected as the study subject. A retrospective study design was employed to collect the patient′s clinical data. Peripheral venous blood sample was collected. Following the extraction of genomic DNA, genetic testing was performed including chromosomal karyotyping analysis, copy number variation sequencing (CNV-seq), multiplex PCR for the AZF regions and sex-determining genes Y ( SRY), and whole-exome sequencing (WES). Candidate variants were validated by Sanger sequencing and classified for pathogenicity based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of Nanjing Drum Tower Hospital (Ethics No.: 2022-451-01). Results:The patient had a height of 188 cm and a body weight of 50 kg, in addition with infantile uterus, absent ovaries, and primary amenorrhea. G-banded karyotyping analysis of peripheral blood sample revealed 47, XYY. CNV-seq indicated Seq[GRCh37]Yp11.32q12×2. No deletion was detected in the AZF regions of Y chromosome, and SRY was positive. WES identified a heterozygous c. 86C>A (p.Thr29Lys) variant of the NR5A1 gene, leading to substitution of threonine with lysine at position 29 of the encoded protein. Sanger sequencing confirmed the presence of the variant. According to the ACMG guidelines, this variant was classified as variant of uncertain significance (VUS) with supporting evidence (PS3_Moderate+ PM5+ PP3+ PM2_Supporting+ PS4_Supporting). Reviewing the nearly 60 years of previously reported cases, all 7 documented 47, XYY DSD patients were assigned a female social gender and presented with abnormal gonadal and external genitalia development. Among them, 5 cases underwent SRY testing, all of which were positive. Only 1 case underwent whole-exome sequencing (WES), but no pathogenic or likely pathogenic variants were identified. Conclusion:This DSD patient presented with the clinical features of tall stature and primary amenorrhea. The NR5A1 gene variant c. 86C>A (p.Thr29Lys) probably underlay the disorder of sex development in this patient. Above finding has enriched the spectrum of pathogenic variants of the NR5A1 gene.
5.Efficacy of non-invasive prenatal testing of fetal free DNA in maternal peripheral blood in fetuses with increased nuchal translucency
Mengyao NI ; Xiangyu ZHU ; Wei LIU ; Leilei GU ; Peixuan CAO ; Ying YANG ; Xing WU ; Chunxiang ZHOU ; Honglei DUAN ; Jie LI
Chinese Journal of Perinatal Medicine 2025;28(2):113-118
Objective:To explore the efficacy of non-invasive prenatal testing (NIPT) of fetal free DNA in maternal peripheral blood in fetuses with increased nuchal translucency (NT).Methods:A retrospective analysis was conducted on 1 184 singleton pregnant women that underwent chromosomal microarray analysis (CMA) at Nanjing Drum Tower Hospital, Nanjing University Medical School from June 2014 to December 2022 due to fetal increased NT (≥3.0 mm). These subjects were categorized based on whether the increased NT was accompanied by other high-risk factors into isolated increased NT without advanced maternal age (further subdivided into 3.0 mm≤NT<3.5 mm, 3.5 mm≤NT<4.0 mm, and NT≥4.0 mm subgroups), isolated increased NT with advanced maternal age, increased NT with nasal bone abnormalities, increased NT with other soft markers, and increased NT with structural abnormalities groups. Assuming the sensitivity and specificity of NIPT and expanded NIPT at this center were both 100%, genomic abnormalities outside the detection range of NIPT or expanded NIPT were termed as residual risk of NIPT or expanded NIPT. Chi-square test and Bonferroni correction were used to compare the residual risks of NIPT and expanded NIPT among the three subgroups of isolated increased NT without advanced maternal age group. Results:(1) In the group of isolated increased NT without advanced maternal age: For the 3.0 mm≤NT<3.5 mm subgroup (329 cases), 19 abnormalities were detected by CMA [12 cases of chromosome aneuploidy, seven cases of pathogenic copy number variation (pCNV)], with residual risks of NIPT and expanded NIPT both at 2.1% (7/329). For the 3.5 mm≤NT<4.0 mm subgroup (173 cases), 29 abnormalities were detected by CMA (17 cases of chromosome aneuploidy, nine cases of pCNV, three cases of chromosome unbalanced translocation), with residual risks of NIPT at 8.1% (14/173) and expanded NIPT at 7.5% (13/173). For the NT≥4.0 mm subgroup (270 cases), CMA detected abnormalities in 70 cases (50 cases of chromosome aneuploidy, 16 cases of pCNV, three cases of unbalanced translocations, and one case of sex chromosome abnormality combined with pCNV). The residual risk of NIPT was 12.2% (33/270), and the residual risk of expanded NIPT was 7.0% (19/270). The residual risks of NIPT and expanded NIPT in the 3.0 mm≤NT<3.5 mm subgroup were lower than those in the 3.5 mm≤NT<4.0 mm and NT≥4.0 mm subgroups (Bonferroni correction, all P<0.017). (2) In the group of 92 cases with isolated increased NT and advanced maternal age, CMA detected abnormalities in 36 cases (29 cases of chromosome aneuploidy, five cases of pCNV, one case of trisomy 21 combined with sex chromosome abnormality, and one case of trisomy 18 combined with sex chromosome abnormality). The residual risk of NIPT was 7.6% (7/92), and that of expanded NIPT was 5.4% (5/92). (3) In the group of 49 cases with increased NT combined with nasal bone abnormalities, CMA detected abnormalities in 24 cases (23 cases of chromosome aneuploidy and one case of pCNV). The residual risks of NIPT and expanded NIPT were both 2.0% (1/49). (4) In the group of 26 cases with increased NT combined with other soft markers, CMA detected abnormalities in nine cases (six cases of chromosome aneuploidy, one case of pCNV, and two cases of chromosome unbalanced translocations). The residual risks of NIPT and expanded NIPT were both 11.5% (3/26). (5) In the group of 245 cases with increased NT combined with structural abnormalities, CMA detected abnormalities in 121 cases (107 cases of chromosome aneuploidy, seven cases of pCNV, four cases of chromosome unbalanced translocations, one case of trisomy 21 combined with trisomy 20, and two cases of trisomy 18 combined with sex chromosome abnormalities). The residual risk of NIPT was 16.7% (41/245), and that of expanded NIPT was 4.1% (10/245). Conclusions:For isolated NT≥3.5 mm or NT≥3.0 mm combined with other high-risk factors, chorionic villus sampling in early pregnancy can be recommended, advancing the timing of prenatal diagnosis from the second trimester to the first trimester. For fetuses with isolated 3.0 mm≤NT<3.5 mm, the 2.1% residual risk of chromosomal abnormalities should be fully informed during counseling, even if the risk of NIPT is low.
6.Prenatal diagnosis and outcome of pregnancy for women with high risks by screening of fetal free DNA from peripheral blood samples
Zhaoxia LI ; Honglei DUAN ; Wei LIU ; Ruifang ZHU ; Jie LI
Chinese Journal of Medical Genetics 2024;41(1):1-7
Objective:To analyze the results of prenatal diagnosis and outcome of pregnancy for women with a high risk for fetal aneuploidies.Methods:A total of 747 cases of prenatal diagnosis by amniocentesis due to high risks by non-invasive prenatal testing (NIPT) were selected from January 2015 to March 2022 in the Drum Tower Hospital Affiliated to Nanjing University Medical School. The amniotic fluid samples were subjected to chromosomal karyotyping and/or chromosomal microarray analysis. All cases were followed up by searching the birth information or telephone calls, and the results were recorded. 2 test or F test were used for comparing the difference between the groups.Results:Among the 747 pregnant women with a high risk by NIPT, 387 were true positives, and the overall positive predictive value (PPV) was 51.81%. The PPVs for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13) and sex chromosome aneuploidies (SCA) were 80.24% (199/248), 60% (48/80), 14% (7/50) and 38.97% (106/272), respectively. The PPV for T21 was significantly higher than T18 and T13 ( χ2= 85.216, P<0.0001). The PPV for other chromosomal aneuploidies and copy number variations (CNVs) were 11.11% (5/45) and 40.74% (22/52), respectively. The PPV for increased X chromosomes was significantly higher than X chromosome decreases (64.29% vs. 22.22%, χ2= 5.530, P<0.05). The overall PPV for elder women (≥ 35 years old) was significantly higher than younger women (69.35% vs. 42.39%, χ2= 49.440, P<0.0001). For T21 and T18, the PPV of Z ≥ 10 group was significantly higher than that for 3 ≤ Z < 5 group or 5 ≤ Z < 10 group ( P<0.05). Among 52 cases with a high risk for CNVs, the PPV for the ≤ 5 Mb group was significantly higher than the 5 Mb < CNVs < 10 Mb or > 10 Mb groups (60% vs. 30%和60% vs. 23.53%, P<0.05). Among the 387 true positive cases, 322 had opted for induced labor, 53 had delivered with no abnormal growth and development, and 12 were lost during the follow-up. Conclusion:The PPVs for common chromosomal aneuploidies are related to the age and Z value of the pregnant women, which were higher in the elder group and higher Z value group. In addition, the PPV is associated with high risk types. The PPV for T21 was higher than T18 and T13, and that for 45, X was lower than 47, XXX, 47, XYY or 47, XXY syndrome. NIPT therefore has relatively high PPVs for the identification of chromosomal CNVs.
7.Analysis of inter room comparison results of internal quality control data for maternal serological prenatal screening in Jiangsu Province from 2021 to 2022
Ying ZHANG ; Honglei DUAN ; Jie LI ; Zhijun JIA
Chinese Journal of Preventive Medicine 2024;58(3):358-363
The relevant data reported by laboratories carrying out serological prenatal screening in Jiangsu Province from 2021 to 2022 were retrospectively analyzed, and the provincial inter-ventricular quality assessment was realized by comparing the internal quality control data of laboratories. The quality control analysis platform of prenatal screening in Jiangsu Province was used to collect the determination methods, quality control data results of three concentrations, instrument platform, reagents and other relevant information of maternal serological screening quality control in early and middle pregnancy in each laboratory from 2021 to 2022. Firstly, the test results of each laboratory were statistically analyzed, and the precision of each laboratory was evaluated by the variation coefficient of indoor quality control. Secondly, the consistency was evaluated by comparing laboratories with different experimental platforms. The results showed that the passing rate of PAPP-A(pregnancy-associated plasma protein-A) precision test in 2021 and 2022 was 87.5% (7/8) and 92.3% (12/13), respectively. The accuracy pass rate of the Free β-hCG (free beta-human chorionic gonadotrophin)(early pregnancy) test in 2021 and 2022 was 97.5% (39/40) and 95.5% (42/44), and the accuracy pass rate of the AFP(alpha-fetal protein) test in 2021 and 2022 was 100% (40/40) and 90.9% (40/44), respectively. The accuracy pass rate of Free β-hCG (middle pregnancy) test in 2021 and 2022 was 100% (40/40) and 95.5% (42/44), respectively. The consistency of each index was 100%. In conclusion, the relevant data reported by laboratories carrying out serological prenatal screening in Jiangsu Province has a high consistency, and for a small number of laboratories with poor stability, it is necessary to make periodic evaluation and rectification according to the data analysis results, so as to improve the quality control management of maternal serological prenatal screening.
8.Analysis of inter room comparison results of internal quality control data for maternal serological prenatal screening in Jiangsu Province from 2021 to 2022
Ying ZHANG ; Honglei DUAN ; Jie LI ; Zhijun JIA
Chinese Journal of Preventive Medicine 2024;58(3):358-363
The relevant data reported by laboratories carrying out serological prenatal screening in Jiangsu Province from 2021 to 2022 were retrospectively analyzed, and the provincial inter-ventricular quality assessment was realized by comparing the internal quality control data of laboratories. The quality control analysis platform of prenatal screening in Jiangsu Province was used to collect the determination methods, quality control data results of three concentrations, instrument platform, reagents and other relevant information of maternal serological screening quality control in early and middle pregnancy in each laboratory from 2021 to 2022. Firstly, the test results of each laboratory were statistically analyzed, and the precision of each laboratory was evaluated by the variation coefficient of indoor quality control. Secondly, the consistency was evaluated by comparing laboratories with different experimental platforms. The results showed that the passing rate of PAPP-A(pregnancy-associated plasma protein-A) precision test in 2021 and 2022 was 87.5% (7/8) and 92.3% (12/13), respectively. The accuracy pass rate of the Free β-hCG (free beta-human chorionic gonadotrophin)(early pregnancy) test in 2021 and 2022 was 97.5% (39/40) and 95.5% (42/44), and the accuracy pass rate of the AFP(alpha-fetal protein) test in 2021 and 2022 was 100% (40/40) and 90.9% (40/44), respectively. The accuracy pass rate of Free β-hCG (middle pregnancy) test in 2021 and 2022 was 100% (40/40) and 95.5% (42/44), respectively. The consistency of each index was 100%. In conclusion, the relevant data reported by laboratories carrying out serological prenatal screening in Jiangsu Province has a high consistency, and for a small number of laboratories with poor stability, it is necessary to make periodic evaluation and rectification according to the data analysis results, so as to improve the quality control management of maternal serological prenatal screening.
9.Influence of maternal autoimmune diseases and anticoagulants on fetal fraction of maternal plasma cell-free DNA
Xuemei CHEN ; Honglei DUAN ; Wanjun WANG ; Ying ZHANG ; Xiangyu ZHU ; Xing WU ; Ying YANG ; Peixuan CAO ; Mengyao NI ; Zihan JIANG ; Biyun XU ; Jie LI
Chinese Journal of Perinatal Medicine 2024;27(6):450-456
Objective:To investigate the influence of maternal autoimmune diseases and anticoagulants, including low-molecular-weight heparin (LMWH) and aspirin, on the fetal fraction of maternal plasma cell-free DNA of non-invasive prenatal testing (NIPT).Methods:A prospective cohort study was conducted on women with singleton pregnancies receiving NIPT in the Nanjing Drum Tower Hospital from March 2021 to July 2022. NIPT was carried out using a polymerase chain reaction (PCR)-free amplification platform. In this study, four types of maternal autoimmune diseases, which were antiphospholipid syndrome, undifferentiated connective tissue disease, Sj?gren's syndrome, and systemic lupus erythematosus (SLE), and two anticoagulants, LMWH and aspirin, were studied. Univariate and multivariate linear regression models were used to analyze the factors influencing fetal fraction of maternal plasma cell-free DNA.Results:A total of 4 102 singleton pregnant women were enrolled in the prospective cohort, and 3 948 were finally included after excluding the cases with unclear dosing time of LMWH or aspirin, other autoimmune diseases, conceiving through ovulation induction alone, and having true positive or failed NIPT result. There were 96 cases with antiphospholipid syndrome, 35 with undifferentiated connective tissue disease, 34 with Sj?gren's syndrome, and 18 with SLE. A total of 108 patients only received LMWH treatment, 121 only received aspirin treatment, and 113 received both LMWH and aspirin treatment. Univariate linear regression analysis showed that maternal body mass index at blood collection ( B=-0.423), conceived by assisted reproductive technology ( B=-0.803), male fetus ( B=-0.458), undifferentiated connective tissue disease ( B=1.774), and SLE ( B=3.467) had influence on the fetal fraction (all P<0.05). Multivariate linear regression analysis showed that maternal body mass index at blood collection ( B=-0.415), conceived by assisted reproductive technology ( B=-0.585), male fetus ( B=-0.322), SLE ( B=3.347) and undifferentiated connective tissue disease ( B=1.336) were factors influencing fetal fraction (all P<0.05). Conclusions:Maternal use of LMWH or aspirin does not affect fetal fraction when performing NIPT on a PCR-free amplification platform, but undifferentiated connective tissue disease and SLE are the influencing factors. Therefore, pregnant women should be informed before the NIPT that the fetal fraction of maternal plasma cell-free DNA may be affected by maternal autoimmune diseases.
10.Detection of an 8p23.1 Inversion Using High-Resolution Optical Genome Mapping
Chunxiang ZHOU ; Huijun LI ; Yiyan SHI ; Linlin HE ; Honglei DUAN ; Jie LI
Maternal-Fetal Medicine 2024;06(3):173-177
Objective::To evaluate the performance of optical genome mapping (OGM) in identifying an inversion located in the short arm of chromosome 8 (8p, 8p23.1), flanked by regions of complex segmental duplication (SD), using the GRCh38 and telomere-to-telomere (T2T) genome references.Methods::We investigated a couple suspected of carrying the 8p23.1 inversion due to a terminal deletion combined with an interstitial duplication of 8p found in their abortus. OGM was performed on both individuals. The data were mapped to the current GRCh38 and the updated T2T genome references, respectively.Results::The 8p23.1 inversion was observed in the female when mapping OGM data to the T2T assembly. In contrast, under the GRCh38 reference, the orientation between the suspected breakpoints within the SD regions could not be distinguished. Additional variants of uncertain significance were also identified in both individuals.Conclusion::Our findings highlight the superiority of the T2T reference in recognizing structural variations involving SD regions. The enhanced SV detection using the T2T reference may contribute to a better understanding of genome instability and human diseases.

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