Birth defects are a major problem threatening the health of children in China. Genetic factors play a major role in birth defect etiology. Molecular diagnosis is the key means for screening, diagnosing, and preventing birth defects caused by genetic factors. How to carry out large-scale and cost-effective molecular diagnosis in clinical practice is a major challenge in the prevention and treatment of birth defects in China. This article reviews the current status of birth defects in China, the application of molecular diagnostic technology in birth defect prevention and control, and the challenges in promoting its use, to provide references for clinical practice in birth defect molecular diagnosis.

Birth defects are a major problem threatening the health of children in China. Genetic factors play a major role in birth defect etiology. Molecular diagnosis is the key means for screening, diagnosing, and preventing birth defects caused by genetic factors. How to carry out large-scale and cost-effective molecular diagnosis in clinical practice is a major challenge in the prevention and treatment of birth defects in China. This article reviews the current status of birth defects in China, the application of molecular diagnostic technology in birth defect prevention and control, and the challenges in promoting its use, to provide references for clinical practice in birth defect molecular diagnosis.

Birth defects and rare diseases have become major public health problems, and early prevention and control are the most effective interventions. In recent years, with the rapid development of genomic techniques such as high-throughput sequencing, the level of screening and diagnosis of genetic birth defects and rare diseases has been greatly improved. This article reviews the application of genomic technologies in the pre-pregnancy, preimplantation, prenatal and neonatal stages, as well as the trend of clinical transformation, highlighting the broad prospects of constructing an early and precise prevention and control system in the era of genomic medicine.

Birth defects and rare diseases have become major public health problems, and early prevention and control are the most effective interventions. In recent years, with the rapid development of genomic techniques such as high-throughput sequencing, the level of screening and diagnosis of genetic birth defects and rare diseases has been greatly improved. This article reviews the application of genomic technologies in the pre-pregnancy, preimplantation, prenatal and neonatal stages, as well as the trend of clinical transformation, highlighting the broad prospects of constructing an early and precise prevention and control system in the era of genomic medicine.

At present, the prevention and control of new coronavirus has entered a critical period. However, the use of quantitative real-time PCR (qRT-PCR) assays for the detection of viral nucleic acid, as a crucial diagnostic approach, has been doubted in clinical practice. Herein, we have reviewed the current status of epidemic prevention and control, latest development of detection technologies, disease characteristics, clinical sampling and transport. We have also discussed the factors that may affect the performance of viral nucleic acid detection, and suggested some effective methods to improve the detection performance of the assays.

As one of the two methods for 2019 novel coronavirus (2019-nCoV), gene sequencing is different from quantitative real-time PCR (RT-PCR) in detection principles. Therefore, gene sequencing has its own pros and cons in clinical application. Currently, metagenomic next-generation sequencing (mNGS) is the most commonly used technology in clinical application. Due to its broad coverage of all types of pathogens, mNGS demonstrates incomparable advantage in rapid identification of novel pathogens such as 2019-nCoV. In addition, it can simultaneously identify other pathogens except 2019-nCoV and mixed infections. On the other hand, however, due to the complexity of mNGS and long detection time, it is unlikely to achieve the purpose of wide-range and rapid diagnosis of 2019 n-CoV. Therefore, mNGS can complement RT-PCR to achieve best clinical application.

At present, the prevention and control of new coronavirus has entered a critical period. However, the use of quantitative real-time PCR (qRT-PCR)assays for the detection of viral nucleic acid, as a crucial diagnostic approach, has been doubted in clinical practice. Herein, we have reviewed the current status of epidemic prevention and control, latest development of detection technologies, disease characteristics, clinical sampling and transport. It has also discussed the factors that may affect the performance of viral nucleic acid detection, and suggested some effective methods to improve the detection performance of the assays.

As one of the two methods for 2019 novel coronavirus (2019-nCoV), gene sequencing is different from quantitative real-time PCR (RT-PCR) in detection principles. Therefore, gene sequencing has its own pros and cons in clinical application. Currently, metagenomic next-generation sequencing (mNGS) is the most commonly used technology in clinical application.Due to its broad coverage of all types of pathogens, mNGS demonstrates incomparable advantage in rapid identification of novel pathogens such as 2019-nCoV. In addition, it can simultaneously identify other pathogens except 2019-nCoV and mixed infections. On the other hand, however, due to the complexity of mNGS and long detection time, it is unlikely to achieve the purpose of wide-range and rapid diagnosis of 2019 n-CoV. Therefore, mNGS can complement RT-PCR to achieve best clinical application.

Intellectual disability (ID) is a group of neurodevelopmental disorders with high heterogeneous in both genotypes and phenotypes and its definitive diagnosis is increasingly dependent ongenome-wide molecular diagnostics.Based on next generation sequencing(NGS), panel sequencing, whole exome sequencing (WES) and even whole genome sequencing are well applied to the molecular diagnosis of ID. Based on these, we recommend WES, especially trio-WES as the preferred detection method. NGS data analysis and reanalysis for ID have clinical significance for diagnosis, and can detect small scale variation and copy number variation in the genome reliably. Therefore, it has the potential to become the next recommended molecular diagnostic toolfor ID.

Neurodevelopmental disorders(NDD)is a spectrum of disorders characterized with impaired development of the neuropsychological system and /or functional insufficiency in children.The etiology of NDD is still secure though genetic defects are known to be closely associated with development and prognosis of NDD.Recently, the diagnostic yield of NDD is significantly enhanced along with the application of high-throughput genomic analysis including chromosomal microarray analysis(CMA), target sequencing,and whole exome sequencing(WES)in clinical practice.In view of the high genetic heterogeneity and significant expression variability of NDD, it′s preferred to perform an integrated genetic analysis with multiple molecular diagnostic platforms in a standard workflow for patients with NDD.What′s more,an expert consensus and/or technological guideline for molecular diagnostics of NDD generated from large-scale multi-center studies on cohorts of Chinese patients with NDD is crucial for improvement of healthcare for patients with NDD in China.