Utility, benefits, and risks of newborn genetic screening carrier reports for families.

Background: Newborn genetic screening (NBGS) based on next-generation sequencing offers enhanced disease detection and better detection rates than traditional newborn screening. However, challenges remain, especially around reporting the NBGS carrier results. Therefore, we aimed to investigate the NBGS carrier parents' views on NBGS and NBGS reports in China. Methods: We distributed a survey querying demographic information, knowledge and perceptions of NBGS, the impact of NBGS on a total of 2930 parents, and their decision-making to parents of newborns reported as carriers in NBGS in Nanjing, China in 2022. Results: The average age of the survey respondents was 30.7 years (standard deviation = 3.6). Most (68.38%) felt informed about NBGS, especially women, the highly educated, and high earners. Nearly all (98.74%) saw NBGS as crucial for early disease detection, with 73.18% believing it positively impacts their future. However, 19.16% felt it might cause anxiety, especially among the less educated. Concerns included potential discrimination due to exposed genetic data and strained family ties. Many suggested NBGS coverage by medical insurance to ease financial burdens. Conclusions: Through our study, we gained insights into parents' perspectives and concerns regarding the NBGS carrier result reporting, thus providing relevant information for further refinement and clinical promotion of the NBGS project.

Newborn genetic screening is highly effective for high-risk infants: A single-centre study in China.

Background: Newborn genetic screening (NBGS) is promising for early detection of genetic diseases in newborns. However, little is known about its clinical effectiveness in special groups like high-risk infants. To address this gap, we aimed to investigate the impact of NBGS on high-risk infants. Methods: We screened 10 334 healthy newborns from the general maternity unit and 886 high-risk infants from the neonatal ward using both traditional newborn screening (tNBS) and NBGS, and collected clinical data from electronic medical records. Results: We found that high-risk infants had a higher proportion of eutocia (P < 0.01) and prematurity (P < 0.01). For high-risk infants vs healthy newborns screened by tNBS, the primary screening positive rate was 3.84% vs 1.31%, the false positive rate (FPR) was 3.62% vs 1.18% (P < 0.001), and the positive predictive value (PPV) was 5.88% vs 8.27%. For NBGS vs tNBS in high-risk infants, the primary screening positive rate was 0.54% vs 3.68%, the FPR was 0.22% vs 3.47%, and the PPV was 60.00% vs 5.88%. Conclusions: We found that combined newborn screening can effectively reduce the FPR caused by the high-risk symptoms and improve the PPV in high-risk infants, sufficient for more accurately showing the true status of the disease.

Folic Acid Rescues Valproic Acid-Induced Morphogenesis Inhibition in Neural Rosettes Derived From Human Pluripotent Stem Cells.

The ability of human pluripotent stem cells (hPSCs) to specialize in neuroepithelial tissue makes them ideal candidates for use in the disease models of neural tube defects. In this study, we cultured hPSCs in suspension with modified neural induction method, and immunostaining was applied to detect important markers associated with cell fate and morphogenesis to verify the establishment of the neural tube model in vitro. We carried out the drug experiments to further investigate the toxicity of valproic acid (VPA) exposure and the potential protective effect of folic acid (FA). The results demonstrated that neural rosette undergoes cell fate speciation and lumen formation accompanied by a spatiotemporal shift in the expression patterns of cadherin, indicating the model was successfully established. The results showed that VPA caused morphogenesis inhibition of lumen formation by altering cytoskeletal function and cell polarization, which could be rescued by FA supplement.

Combined genetic screening and traditional biochemical screening to optimize newborn screening systems.

Newborn screening can detect around 40 different diseases based on biochemical indicators and has resulted in the improved quality of life for children suffering from genetic diseases. However, NBS is limited as it does not cover all genetic diseases in newborns and has high rates of false positives and negatives. Genetic screening can be used to address the shortcomings of traditional biochemical screening, however, the comprehensive clinical value of genetic screening is yet to be systematically studied. In this study, we used two different genetic screening methods to examine 200 cases of NBS. We found that genetic screening can be used to identify a broader spectrum of diseases and is not limited to traditional biochemical screening diseases; it can identify positive cases of disease and can eliminate false positives caused by multiple factors such as pathogenic variants carrier or the mode of childbirth. Genetic screening has shortened the time to diagnosis and reduced the costs of testing. Furthermore, we found that the biochemical detection results were limited when patients simultaneously carried multiple pathogenic mutations. Our research provisionally demonstrates the necessity, feasibility and significance of clinical genetic screening in newborns and provides a solid basis for future clinical developments.

Two factors affecting the success rate of the second non-invasive prenatal screening after initial no-call result: experience from a single tertiary center in China.

BACKGROUND: One inevitable shortcoming of non-invasive prenatal screening (NIPS)/cell-free DNA (cfDNA) sequencing is the uninterpretable ("no-call") result, which is mainly caused by an insufficient fetal fraction. This study was performed to investigate the factors associated with a successful second NIPS in these cases and determine the optimal management for women with initial no-call results. METHODS: We retrospectively analyzed the data of women who underwent NIPS with initial no-call results due to an insufficient fetal fraction from 2017 to 2019 in our center. We compared these women's maternal and pregnancy information with the data of women who had attained a successful second NIPS result and women who had received no-call results for a second time. RESULTS: Among the 33,684 women who underwent NIPS, 137 with a no-call result underwent a retest. Comparison between the 87 (63.50%) women with a successful retest and the other 50 (36.50%) women showed a significant difference in both the initial fetal fraction and maternal body mass index (BMI), whereas the other factors showed no significant differences. In addition, with an initial fetal fraction of < 2.00%, the retest success rate was very limited. CONCLUSIONS: We identified two major factors associated with a successful NIPS retest: the initial fetal fraction and the maternal BMI. These findings suggest the need for specialized management for this subset of women and would be instructional for the counseling for these women.

Integrated metagenomics and metabolomics analysis of third-trimester pregnant women with premature membrane rupture: a pilot study.

BACKGROUND: Premature rupture of membranes (PROM) is a major pregnancy complication in China and usually leads to adverse pregnancy outcomes. The major aim of this study was to search for microorganisms and their related metabolites that have direct relationship with PROM. METHODS: For vaginal discharge samples, metagenomics sequencing was applied to identify microorganisms that were enriched in PROM subjects, and untargeted metabolomics was applied to characterize the metabolites changes in PROM subjects compared to healthy controls (HC). Correlation analysis was then used to explore the relationship between these microorganisms and metabolites changes. RESULTS: Two upstream metabolites of glycolysis, N-acetyl-D-galactosamine (GalNAc) and sucrose, were found downregulated in the PROM group (P=0.04 and P=0.041, respectively). Higher percentages of conditional pathogens, such as of Streptococcus (8.4% vs. 6.1% in HC group, P=0.15) and Chlamydia (4.3% vs. 2.3% in HC group, P=0.07) were found in PROM group. Other common conditional pathogens including Prevotella, Staphylococcus, Mycobacterium and Enterobacter, were also higher in PROM group, although their absolute percentages were low and the differences did not reach statistical significance due to relative small sample size. Correlation analysis further demonstrated a positive correlation of downregulation of glycolysis metabolites with higher percentage of conditional pathogens. CONCLUSIONS: Integrated metagenomics and metabolomics analysis can be used to track the subtle changes in the vaginal microenvironment. Downregulation of glycolysis substrates (GalNAc and sucrose) and increase of related pathogenic microorganisms (Streptococcus and Chlamydia) could serve as early warning biomarkers of PROM.

Detection of Vaginal Metabolite Changes in Premature Rupture of Membrane Patients in Third Trimester Pregnancy: a Prospective Cohort Study.

Premature rupture of membranes (PROM) is usually associated with pregnant and neonatal complications. Most of the PROM cases are caused by ascending asymptomatic genital infection. In China, PROM (15.3%) is more common than spontaneous preterm labor (7.3%) and leads to more adverse pregnancy outcomes. Here, we designed a prospective cohort study to measure the metabolomics changes in vaginal swab samples and explored their potential contribution to PROM. A total of 260 differentially expressed metabolites were identified and further analyzed. In the PROM group, N-acetyl-D-galactosamine and sucrose were downregulated (P = 0.0025, P = 0.0195, respectively), both of which are the upstream metabolites of the glycolysis pathway. Furthermore, estriol 3-sulfate 16-glucuronide (P = 0.0154) and 2-methoxy-17beta-estradiol 3-glucosiduronic acid (P = 0.004), two final metabolites in steroid hormone biosynthesis, were both downregulated in the PROM group. Finally, we found two catechin metabolites (epigallocatechin-7-glucuronide, P = 0.0009; 4'-methyl-epigallocatechin-7-glucuronide, P = 0.01) as well as DL-citrulline (P = 0.0393) were also significantly downregulated in the PROM group compared with the healthy control (HC) group, which are related to important antioxidant and anti-inflammatory activities in the human body. Altogether, metabolite changes in glycolysis, steroid hormone biosynthesis, and antioxidant/anti-inflammatory pathways may contribute to (or be a consequence of) vaginal dysbiosis and PROM. Metabolite pathway analysis is a new and promising approach to further investigate the mechanism of PROM and help prevent its unfavorable pregnant outcomes at a functional level. Trial registration number: ChiCTR2000034721.

Rapid screening for Klinefelter syndrome with a simple high-resolution melting assay: a multicenter study.

Klinefelter syndrome (KS) is the set of symptoms that result from the presence of an extra X chromosome in males. Postnatal population-based KS screening will enable timely diagnosis of this common chromosomal disease, providing the opportunity for early intervention and therapy at the time point when they are most effective and may prevent later symptoms or complications. Therefore, through this study, we introduced a simple high-resolution melting (HRM) assay for KS screening and evaluated its clinical sensitivity and specificity in three medical centers using 1373 clinical blood samples. The HRM assay utilized a single primer pair to simultaneously amplify specific regions in zinc finger protein, X-linked (ZFX) and zinc finger protein, Y-linked (ZFY). In cases of KS, the ratios of ZFX/ZFY are altered compared to those in normal males. As a result, the specific melting profiles differ and can be differentiated during data analysis. This HRM assay displayed high analytical specificity over a wide range of template DNA amounts (5 ng-50 ng) and reproducibility, high resolution for detecting KS mosaicism, and high clinical sensitivity (100%) and specificity (98.1%). Moreover, the HRM assay was rapid (2 h per run), inexpensive (0.2 USD per sample), easy to perform and automatic, and compatible with both whole blood samples and dried blood spots. Therefore, this HRM assay is an ideal postnatal population-based KS screening tool that can be used for different age groups.

[Mutational spectrum of phenylalanine hydroxylase gene and identification of novel mutations in patients with hyperphenylalaninemia in Jiangsu province].

OBJECTIVE: To study the characteristics of phenylalanine hydroxylase (PAH) gene mutations in patients with hyperphenylalaninemia from Jiangsu province by DNA sequencing, and to analyze the spectrum of PAH gene mutations. METHODS: A total of 70 patients and their parents were included in this study. All of the 13 exons and flanking introns of the PAH gene were analyzed with DNA sequencing. RESULTS: Forty five types of mutations were identified, which included 4 novel mutations (L37P, H107R, Q267L, S391T). A total of 125 mutations were identified in 140 alleles (89.3%). All mutations were detected in exons 2-3, 5-7, 9-12 and introns 2, 4, 7 and 8. Most mutations were found in exons 6, 7 and 12. EX6-96A > G, R243Q and R241C were the most common mutations. CONCLUSION: The mutational spectrum of Jiangsu province seems to be different from other regions. The spectrum can offer reliable information for genetic diagnosis of patients with hyperphenylalaninemia.

1q25.2-q31.3 Deletion in a female with mental retardation, clinodactyly, minor facial anomalies but no growth retardation.

The reports of 1q25-32 deletion cases are rare. We reported here an 11-year-old Chinese Han female with an interstitial 1q25 deletion displaying mental retardation, clinodactyly of the 5th finger and minor facial anomalies. Notably, the patient did not present growth retardation which is quite common in patients with 1q25-32 deletion encompassing LHX4. The heterozygous deletion in this patient was characterized as 46,XX,del(1)(q25.2-q31.3) with a length of 20.5 Mb according to SNP-array test results. STRP (Short Tandem Repeat Polymorphism) analysis of the family trio indicated the genomic abnormality was de novo with paternal origin. After a genotype-phenotype analysis, we proposed here the loss of a 3.1 Mb critical region including 24 genes within 1q25.2 (chr1:174.5-177.6 Mb, build 36) may account for the mental retardation in patients with 1q25-32 deletion.

[Molecular diagnosis of OTC gene mutation in a Chinese family with ornithine transcarbamylase deficiency].

OBJECTIVE: To detect potential mutations of OTC gene in a male infant affected with ornithine transcarbamylase deficiency. METHODS: Genomic DNA were isolated from peripheral blood samples of family members and 100 healthy individuals. Potential mutations of the 10 exons of OTC gene were screened with PCR and Sanger sequencing. RESULTS: A homozygous missense mutation c.917G>C in exon 9, which results in p.R306T, was identified in the infant. Sequencing of the mother and two female members of the family indicated a heterozygous status for the same mutation. The same mutation was not found in other members of the family and 100 healthy controls. CONCLUSION: A missense mutation c.917G>C in the OTC gene is responsible for the pathogenesis of the disease. Identification of the mutation can facilitate prenatal diagnosis and genetic counseling for the family.

[Development and application of a method for molecular diagnosis of 21-hydroxylase deficiency].

OBJECTIVE: To develop a method for elucidating genetic basis of 21-hydroxylase deficiency. METHODS: Sanger sequencing of entire 21-hydroxylase coding gene CYP21A2 was carried out to detect point mutations, and multiplex ligation-dependent probe amplification (MLPA) and locus-specific PCR/enzyme restriction method were used to detect large deletions and conversion mutations. RESULTS: Nine children were analyzed. Point mutations of the CYP21A2 gene have been identified as: IVS2 13A/C>G (9 alleles), p.Arg356Trp (1 allele), Cluster E6 (1 allele), p.Gln318X (1 allele), and Prom conv (1 allele). While the former 4 mutations are pathogenic, the role of Prom conv mutation in the pathogenesis was uncertain. Three cases had entire CYP21A2 gene deletions (3 alleles), three had CYP21A1P/CYP21A2 chimeric mutations (3 alleles). The genotypes of all patients were determined. And all of the mutations were inherited from parents. CONCLUSION: A rational method for detecting point mutations and large deletions/conversions of CYP21A2 gene has been established.

[Prenatal diagnosis of 22q11.2 microdeletion by multiplex ligation-dependent probe amplification].

OBJECTIVE: To explore the clinical value of multiplex ligation-dependent probe amplification (MLPA) technique performed in prenatal diagnosis of chromosome 22q11.2 microdeletion. METHODS: MLPA was performed to detect chromosome 22q11.2 mircodeletion in 62 fetuses with congenital heart defects by fetal echocardiography and a normal karyotype by standard G-banding analysis.For a 22q11.2 mircodeletion fetus, his parents were detected to know if it is inherited or de novo. The microdeletion was confirmed by array-based comparative genomic hybridization (arrayCGH). RESULTS: MLPA revealed five 22q11.2 mircodeletions in the 62 fetuses, and the positive detection rate was 8% (5/62). Among these, 4 cases carried the 3M typically deletion which all are de novo, and 1 case carried the 1.5M non-typically deletion which was inherited from his father.arrayCGH confirmed the 22q11.2 microdeletions and delineated the precise location and size of microdeletions. CONCLUSION: MLPA has clinical value in prenatal diagnosis of 22q11.2 mircodeletion, which could provide important genetic information for genetic consulting, pregnancy management and intervention after birth.

[Prenatal diagnosis of two fetuses with de novo small supernumerary markers by single nucleotide polymorphism array based comparative genomic hybridization].

OBJECTIVE: To explore the origins of small de novo mosaic supernumerary marker chromosomes (mars) in two fetuses, and to assess the feasibility of single nucleotide polymorphism array-based comparative genomic hybridization (SNP-array CGH) for prenatal molecular cytogenetic diagnosis. METHODS: Two fetuses with de novo were identified. SNP-array marker chromosomes was applied to define the location and range of marker chromosomes. The karyotype of fetus I was determined to be 47,XX,+ mar[23]/46,XX[16], and that of fetus II was 47,XX,+ mar. Multiplex ligation-dependent probe amplification (MLPA) was applied to verify the genomic imbalance found in fetus II. The karyotypes of parents were normal in both families. RESULTS: SNP-array CGH has indicated a 8.3 Mb duplication at 9p21.1-p21.3 in fetus I, and a 10.8 Mb duplication at 15q11.2-q13.3 in fetus II. MLPA has also confirmed a 15q terminal duplication in fetus II. CONCLUSION: Above cases have illustrated that SNP-array CGH is a rapid, powerful and sensitive technique which may be used for identify the origins of marker chromosomes in prenatal diagnosis.

[Array-based comparative genomic hybridization detection of copy number variations in a fetus with hypoplastic left-heart syndrome].

OBJECTIVE: To detect the copy number variations (CNVs) of a fetus with hypoplastic left-heart syndrome, and to assess the value of array-based comparative genomic hybridization (array-CGH) for molecular cytogenetic diagnosis. METHODS: The whole genome of a fetus with normal karyotype by G-banding was scanned and analyzed by array-CGH, and the CNVs was confirmed by multiplex ligation-dependent probe amplification (MLPA). RESULTS: Two submicroscopic CNVs [del(11)(q24.1-ter)(121951443-134449216, -12.50 Mb),dup(15)(q26.3)(96889082-100215359, -3.33 Mb)] were identified and mapped by array-CGH. MLPA test confirmed both CNVs. CONCLUSION: Del (11) (q24.1-ter) may contribute to hypoplastic left-heart syndrome of the fetus. For its high-resolution and high-accuracy, array-CGH has provided a powerful tool for detection of genomic imbalance.

[Second trimester screening for trisomy 21 using ADAM12-S as a maternal serum marker].

OBJECTIVE: To investigate the value of a disintegrin and metalloproteinase 12 secreting form (ADAM12-S) as a maternal serum marker in second trimester screening for trisomy 21 (Down syndrome, DS), and to develop an appropriate prenatal DS screening protocol. METHODS: Serum samples were collected from 53 pregnant women carrying a trisomy 21 fetus and 621 pregnant women with matched gestational age and weight carrying a healthy fetus. ADAM12-S concentrations were determined with a time-resolved fluorescence immunoassay (TRFIA). Curve fitting by weighted regression and other statistical methods were conducted, and the model was optimized for prenatal trisomy 21 screening program in second trimester. ADAM12-S alone or in combination with other two- or three-combination test was selected as a serum marker for prenatal second-trimester screening of trisomy 21 by calculation of detection rate (DR) and false positive rate (FPR). RESULTS: By comparison, the median multiple of the median (MoM) value of ADAM12-S in DS pregnancy group was higher than that of the control group (P< 0.01). When FPR = 5%, the DR of ADAM12-S was 28.3%, and the positive and negative likelihood ratios were 5.66 and 0.75, respectively. The DR of three-combination test of ADAM12-S, alpha-fetoprotein (AFP) and free beta subunit of human chorionic gonadotropin (ß-HCG) has increased to 52.80% from 39.62% of the conventional two-combination test (AFP and free ß-HCG). For women with a risk between 1/300 and 1/1000 by two-combination test for DS, the DR has increased from 39.62% to 47.12%, but FPR only increased by 0.8% after adding ADAM12-S as a maternal serum marker. CONCLUSION: Considering the increased DR of pregnancies with a risk between 1/300 and 1/1000 in second trimester, ADAM12-S may provide a feasible maternal serum maker when combined with AFP and free ß-HCG. The cost-effectiveness ratio is reasonable.

[Cytogenetic analysis of a complex chromosomal imbalance 14q+ in a fetus featuring multiple congenital defects].

OBJECTIVE: To analyze chromosomal imbalance in a fetus presenting with congenital heart disease and mild lateral ventriculomegaly, and to investigate the correlation between genotype and phenotype. The etiology of the fetal congenital diseases was determined, and the feasibility of array-based comparative genomic hybridization (array-CGH) application in molecular cytogenetic diagnosis was evaluated. METHODS: Following conventional G-banding analysis, array-based comparative genomic hybridization (array-CGH) was applied to delineate the precise location and size of genomic imbalance. RESULTS: A de novo 46, XY, -14, +der14(q31)? karyotype was identified in the fetus by G-banding analysis. Array-CGH has verified the chromosomal imbalance to be 46, XY, -14, +der(12; 14) (p13; q32.33)del(14) (q32.33→ qter). CONCLUSION: del(14)(q32.33→ qter) is probably the predominant cause of the fetal congenital disease. For its high resolution and accuracy, array-CGH has provided a powerful tool for prenatal diagnosis and genetic counseling.

[Detection of 9p partial trisomy using array-based comparative genomic hybridization].

OBJECTIVE: To detect chromosomal aberrations in a child with developmental delay and speech and language disorders in order to explore the underlying genetic causes of congenital malformation, and to investigate the feasibility of array-based comparative genomic hybridization (array-CGH) for molecular genetic diagnosis. METHODS: G-banding and array-CGH were applied to characterize the genetic abnormality in the three family members. RESULTS: G-banding analysis revealed the affected child and the healthy mother are both carriers of inv(9)(p13q13), while the child has carried a chromosome fragment derived from chromosome 13. Array-CGH analysis indicated the derivative chromosome fragment has originated from 9p with breakpoints at around 9p13.1-p24.3. CONCLUSION: Trisomy 9p13.1-p24.3 may be the cause of congenital malformation in the child. For its high resolution and high accuracy, array-CGH is a powerful tool for genetic analysis.