Accurate timing of myelination is crucial for the proper functioning of the central nervous system. Here, we identified a de novo heterozygous mutation in TMEM63A (c.1894G>A; p. Ala632Thr) in a 7-year-old boy exhibiting hypomyelination. A Ca²⁺ influx assay suggested that this is a loss-of-function mutation. To explore how TMEM63A deficiency causes hypomyelination, we generated Tmem63a knockout mice. Genetic deletion of TMEM63A resulted in hypomyelination at postnatal day 14 (P14) arising from impaired differentiation of oligodendrocyte precursor cells (OPCs). Notably, the myelin dysplasia was transient, returning to normal levels by P28. Primary cultures of Tmem63a^-/- OPCs presented delayed differentiation. Lentivirus-based expression of TMEM63A but not TMEM63A_A632T rescued the differentiation of Tmem63a^-/- OPCs in vitro and myelination in Tmem63a^-/- mice. These data thus support the conclusion that the mutation in TMEM63A is the pathogenesis of the hypomyelination in the patient. Our study further demonstrated that TMEM63A-mediated Ca²⁺ influx plays critical roles in the early development of myelin and oligodendrocyte differentiation.
Animals ; Cell Differentiation/physiology* ; Oligodendroglia/metabolism* ; Mice, Knockout ; Mice ; Male ; Myelin Sheath/metabolism* ; Humans ; Child ; Cells, Cultured ; Oligodendrocyte Precursor Cells/metabolism*

Objective:To assess the application value of CNVPLUS ?-array for the genetic analysis of spinal muscular atrophy (SMA). Methods:From June 2021 to December 2022, CNVPLUS ?-array technique was employed to test the SMN1 and SMN2 genes among peripheral blood samples from 17 suspected SMA patients, 18 core families with suspected SMA, and 25 healthy individuals. The results were compared with those of multiple ligation-dependent probe amplification (MLPA) assay. Samples with inconsistent results were subjected to nested PCR or comprehensive analysis of SMA. This study was approved by the Shanghai Institute for Pediatric Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (Ethics No. XHEC-D-2024-038). Results:CNVPLUS ?-array has identified 35 SMA patients, 36 carriers, and 25 healthy individuals. In comparison, MLPA has identified 34 SMA patients, 36 carriers, and 26 healthy individuals. The two methods demonstrated a high consistency ( Kappa = 0.968, P<0.001). Additionally, CNVPLUS ?-array has identified one patient with compound heterozygous variants of SMN1 and one carrier with a [2+ 0] genotype. Conclusion:CNVPLUS ?-array not only can accurately determine the copy numbers of SMN1 and SMN2 genes, but also identify point mutations in SMN1 and [2+ 0] carriers, which has offered a new method for the genetic testing of SMA.

To explore the value of CNVPLUS ?-array in the diagnosis of the DMD gene. A retrospective study was performed on 96 children who were clinically diagnosed with Duchenne or Becker muscular dystrophies(DMD/BMD) at the Department of Pediatric Endocrinology and Genetics of Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine from January 2014 to March 2023. DNA was extracted from these children′s peripheral blood and divided into two parts. Variations of the DMD gene were detected by using CNVPLUS ?-array and sequential testing of MLPA—NGS—Sanger. In the sequential method, single exon deletions detected by MLPA were first verified by polymerase chain reaction (PCR) and then were tested by Sanger′s sequencing if PCR results were normal. The results showed that, among 96 samples, 91 cases with the pathogenic variation of the DMD gene were detected by the CNVPLUS ?-array, including 76 cases with large deletion/duplication (copy number variation, CNV) and 15 cases with small variation (single nucleotide variant or small insertion/deletion, SNV/Indel). All samples were tested and diagnosed within 5 days. In contrast, 76 cases with pathogenic CNV and 20 cases with pathogenic SNV/Indel were detected in the DMD gene by sequential method. However, all of the experiments and diagnoses were completed within 48 days. Moreover, 5 cases with SNV/Indel in the DMD gene were correctly clustered after the operation mode was optimized. In summary, as a new micro-array integrating CNV and SNV probes, CNVPLUS ?-array can detect CNV and SNV/Indel in the DMD gene simultaneously while the application of CNVPLUS ?-array could save a lot of time and manpower. CNVPLUS ?-array had an excellent diagnostic performance for CNV of the DMD gene. As for SNV/Indel, the diagnostic performance was slightly poor and the operation mode should be optimized. If necessary, other testing technologies should be supplemented to reduce the risk of missed diagnosis.

To explore the value of CNVPLUS ?-array in the diagnosis of the DMD gene. A retrospective study was performed on 96 children who were clinically diagnosed with Duchenne or Becker muscular dystrophies(DMD/BMD) at the Department of Pediatric Endocrinology and Genetics of Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine from January 2014 to March 2023. DNA was extracted from these children′s peripheral blood and divided into two parts. Variations of the DMD gene were detected by using CNVPLUS ?-array and sequential testing of MLPA—NGS—Sanger. In the sequential method, single exon deletions detected by MLPA were first verified by polymerase chain reaction (PCR) and then were tested by Sanger′s sequencing if PCR results were normal. The results showed that, among 96 samples, 91 cases with the pathogenic variation of the DMD gene were detected by the CNVPLUS ?-array, including 76 cases with large deletion/duplication (copy number variation, CNV) and 15 cases with small variation (single nucleotide variant or small insertion/deletion, SNV/Indel). All samples were tested and diagnosed within 5 days. In contrast, 76 cases with pathogenic CNV and 20 cases with pathogenic SNV/Indel were detected in the DMD gene by sequential method. However, all of the experiments and diagnoses were completed within 48 days. Moreover, 5 cases with SNV/Indel in the DMD gene were correctly clustered after the operation mode was optimized. In summary, as a new micro-array integrating CNV and SNV probes, CNVPLUS ?-array can detect CNV and SNV/Indel in the DMD gene simultaneously while the application of CNVPLUS ?-array could save a lot of time and manpower. CNVPLUS ?-array had an excellent diagnostic performance for CNV of the DMD gene. As for SNV/Indel, the diagnostic performance was slightly poor and the operation mode should be optimized. If necessary, other testing technologies should be supplemented to reduce the risk of missed diagnosis.

Medication during pregnancy is widespread, but there are few reports on its fetal safety. Recent studies suggest that medication during pregnancy can affect fetal morphological and functional development through multiple pathways, multiple organs, and multiple targets. Its mechanisms involve direct ways such as oxidative stress, epigenetic modification, and metabolic activation, and it may also be indirectly caused by placental dysfunction. Further studies have found that medication during pregnancy may also indirectly lead to multi-organ developmental programming, functional homeostasis changes, and susceptibility to related diseases in offspring by inducing fetal intrauterine exposure to too high or too low levels of maternal-derived glucocorticoids. The organ developmental toxicity and programming alterations caused by medication during pregnancy may also have gender differences and multi-generational genetic effects mediated by abnormal epigenetic modification. Combined with the latest research results of our laboratory, this paper reviews the latest research progress on the developmental toxicity and functional programming alterations of multiple organs in offspring induced by medication during pregnancy, which can provide a theoretical and experimental basis for rational medication during pregnancy and effective prevention and treatment of drug-related multiple fetal-originated diseases.

Dystrophinopathies, including Duchenne muscular dystrophy, Becker muscular dystrophy and dilated cardiomyopathy, are X-linked recessive genetic disorders due to variants of the dystrophin gene, which can seriously affect quality of life and health. Genetic diagnosis plays a crucial role in their diagnosis, treatment, and prevention. How to rationally select and standardize the use of various genetic techniques is a skill that clinicians must acquire. By compiling expertise of experts from the relevant areas and guidelines published home and abroad, this consensus has provided a guidance from the perspective of genetic diagnosis for the selection of genetic techniques, testing strategies, and detection process for dystrophinopathies.
Humans ; Quality of Life ; Consensus ; Dystrophin/genetics* ; Muscular Dystrophy, Duchenne/therapy* ; Cardiomyopathy, Dilated/genetics* ; Electrocardiography

21 hydroxylase deficiency (21-OHD), the most common form of congenital adrenal hyperplasia, is caused by defects in CYP21A2 gene, which encodes the cytochrome P450 oxidase (P450C21) involved in glucocorticoid and mineralocorticoid synthesis. The diagnosis of 21-OHD is based on the comprehensive evaluation of clinical manifestation, biochemical alteration and molecular genetics results. Due to the complex structure of CYP21A2, special techniques are required to perform delicate analysis to avoid the interference of its pseudogene. Recently, the state-of-the-art diagnostic methods were applied to the clinic gradually, including the steroid hormone profiling and third generation sequencing. To standardize the laboratory diagnosis of 21-OHD, this consensus was drafted on the basis of the extensive knowledge, the updated progress and the published consensuses and guidelines worldwide by expert discussion organized by Rare Diseases Group of Pediatric Branch of Chinese Medical Association, Medical Genetics Branch of Chinese Medical Doctor Association, Birth Defect Prevention and Molecular Genetics Branch of China Maternal and Child Health Association. and Molecular Diagnosis Branch of Shanghai Medical Association.
Child ; Humans ; Adrenal Hyperplasia, Congenital/genetics* ; Steroid 21-Hydroxylase/genetics* ; Consensus ; China ; Clinical Laboratory Techniques ; Mutation

Newborn screening is an effective measure for early detection and early treatment of rare genetic diseases. Among the three-level preventive measures to reduce birth defects, newborn screening has a significant preventive effect, and continues to develop with the advancement of new therapies and new technologies. Newborn screening is also relatively more reliable to obtain data on the prevalence of rare diseases. This article introduces the history and current status of neonatal screening for newborn hereditary metabolic disease in China, presents the disease spectrum and prevalence of 7 819 662 cases of neonatal screening by tandem mass spectrometry, and proposes 12 rare diseases as the primary targeting diseases for newborn screening by tandem mass spectrometry in China. At last, the article raises and discusses the issues of requirement for technology development and ethics of newborn screening.

Objective:To summarize the clinical manifestation and genetic characteristics of Chinese patients with achondroplasia (ACH) which is caused by pathogenic variants fibroblast growth factor receptor 3 (FGFR3) gene and establish the reference value of height centiles and height for age growth curve of patients for a more practical, simple and useful growth evaluation tool in China.Methods:Through a nationwide cross-sectional survey in China from July 2019 to January 2020 designed by Department of Pediatric Endocrinology and Genetics, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 210 subjects (110 boys, 100 girls), who harbored the pathogenic variant of FGFR3 gene and were diagnosed with achondroplasia, were recruited. The clinical and genetic data of enrolled subjects were collected and analyzed to explore the clinical genetic characteristics of Chinese ACH patients. Furthermore, according to the data of height (body length under 2 years old) of boy and girl subjects aged 0-12 years, centiles and height for age growth curve of achondroplasia were calculated and established by LMS method respectively.Results:The characteristic clinical manifestations of 210 Chinese patients (0-14 years old) were disproportionate short stature (206/210, 98.1%), macrocephaly and characteristic facial features (205/210, 97.6%), trident configuration of the hands (191/210, 90.9%), limbs deformity (156/210, 74.3%), together with normal intelligence. Up to 81.9% (172/210) of patients have different complications, and the kyphosis (121/210, 57.6%) and narrow thoracic (79/210, 37.6%) are common complications. Besides, up to 98.6% (207/210) of patients harbored hotspot variants of FGFR3 gene which cause G380R amino acid substitutions. It is notable that the growth pattern of boy and girl patients (0-12 years old) is obviously different from the normal children ( t=9.849, 9.596, P<0.01) respectively. The height different between ACH patients and normal children gradually widened with age. The average height of the boy (49.2 cm) and girl patients(48.4 cm) of achondroplasia at birth was -1.22 s and -2 s, however, at the age of twelve, the average height of the boy(113.7 cm) and girl patients(112.4 cm) of achondroplasia was -5.23 s and -6.15 s compared to currently standard reference height for age growth curve of normal children in China, respectively. Conclusions:The results of our study demonstrated that in China disproportionate short stature, macrocephaly and characteristic facial features were typical manifestations of ACH patients, and that up to 98.6% of patients harbored hotspot variants of FGFR3 gene. In addition, the reference value of height centiles and height for age growth curve of ACH patients we establish will be a valuable tool for evaluating the growth pattern, monitoring factors affecting growth, estimating ultimate height, and assessing the curative effect of growth-promoting treatments in Chinese patients with achondroplasia.

Objective: To investigate the effect of pseudodeficiency alleles on the newborn screening of glycogen storage disease type Ⅱ(GSDⅡ) by using afluorometric enzymatic assay to determine acid α-glucosidase (GAA) activity in dried blood spot (DBS). Methods: A total of 30 507 newborns′ DBSs, obtained from Newborn Screening Center of Xinhua Hospital Shanghai Jiao Tong University School of Medicine from May to December 2017, were screened for GSD Ⅱ by fluorometric enzymatic assay of GAA activity. The suspected positive DBSs after the first and second screening were directly analyzed by Sanger sequencing of GAA to confirm the diagnosis. Retrospective analysis of 3 172 controls without GSDⅡand 36 GSD Ⅱ patients were conducted to investigate the carrier status of pseudodeficiency alleles. Statistical analysis of frequency of pseudodeficiency alleles were carried out by Chi-square test or Fisher exact probability test. Results: GAA activity of 30 507 newborns showed a positively skewed distribution.Twenty-nine cases of newborns, suspected to be GSDⅡwere confirmed to be normal with genetic analysis of the original DBSs. Among the 29 suspected positive cases, 24 cases were homozygous for pseudodeficiency alleles c.[1726A/A; 2065A/A], and the other 5 cases were c.[1726G/A; 2065G/A] heterozygote. The frequency of c.1726G>Ahomozygote in 3 172 non-GSD Ⅱcontrols was 2.08% (66/3 172), and c.1726G>A homozygote occurred in allelic conjunction with c.2065G>Ahomozygote. Frequency of c.[1726A; 2065A] haplotype in 3 172 controls was 3.2%(206/6 344). Frequency of c.[1726A/A; 2065A/A] homozygote in 36 GSDⅡpatients (16.67%, 6/36) was significantly higher than that in non-GSD Ⅱcontrols(2.08%, 66/3 172) (χ²=34.517, P<0.001). Conclusions Pseudodeficiency alleles show a high frequency in Chinese, which leads to a high false positive rate in the newborns screening of GSDⅡ.The afterword genetic analysis of the original DBS after the GAA activity screening could reduce the effect of pseudodeficiency alleles on the newborns screening of GSDⅡ.