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Thalassemia is one of the most common inherited diseases in Guangxi, China. Early identification of thalassemia by neonatal screening is beneficial for effective clinical management and treatment. A total of 3671 newborns from multiple centers of Guangxi were prospectively recruited and screened for thalassemia using single molecule real-time (SMRT) sequencing technology. A total of 36 types of variants of globin genes were identified, including 16 common variants and 20 rare variants in the Chinese population. In total, 956 (26.04%) newborns were identified to carry thalassemia variants, including 672 (18.31%) α-thalassemia, 228 (6.21%) β-thalassemia, 55 (1.50%) combined α/β-thalassemia and 1 (0.03%) δ-thalassemia. In addition, this study showed that the carrier rates of structural variants of α-globin genes and abnormal hemoglobin variants were 1.28% and 0.93% respectively. Phenotypically, 12 newborns with hemoglobin H disease and 2 cases with intermedia β-thalassemia were found, two of whom would be misdiagnosed by conventional genetic analysis methods. Collectively, this study characterized the complexity and diversity of thalassemia gene variants in newborns of Guangxi, and further achieved early identification of newborns with intermedia thalassemia, which facilitated precision prevention of thalassemia in this region. Also, SMRT provided a powerful tool for neonatal thalassemia screening, especially in prevalent regions.

Background Thalassemia, a hereditary hemolytic blood disorder, is characterized by high global allele prevalence and a gradually expanding variant spectrum. In Guangxi, China, routine genetic screening targeting hotspot variants of thalassemia has been implemented for over a decade, significantly reducing the incidence of severe cases. This study assessed the efficacy of the existing thalassemia screening protocol in Guangxi, China, by applying long-read sequencing (LRS) in family trios/quartets analysis for newborns. Methods This study enrolled 1491 families for the family trios/quartets analysis, among which at least one of the parents had undergone routine genetic screening for thalassemia. A total of 1516 newborns from these families were tested using LRS. The efficacy of routine screening was assessed by comparing detection results across generations. Results α-thalassemia demonstrated higher prevalence than β-thalassemia among newborns, with -- SEA and HBB c.52A > T as the predominant variants. Among the 1516 newborns, 1348 (88.92%) exhibited LRS results that were concordant with the predictions from parental screening. Of these 1348 newborns, 28 had parents who had undergone routine prenatal diagnosis. Discordance between the predictions from parental screening and newborn test results occurred in 168 cases (11.08%), with 154 (10.16%) of these attributable to genetic testing of only one of the parents or incomplete testing of both parents, while the remaining 14 (0.92%) were attributed to limitations of routine methods in detecting complex structural variants and rare point mutations. Conclusions Although routine genetic screening targeting hotspot variants is highly effective, its precision is constrained by strategic and methodological limitations. A comprehensive and accurate LRS-based screening method can serve as a valuable supplement to routine screening, enhancing the precision of thalassemia prevention and management.

Background Deletion or duplication in the DMD gene is one of the most common causes of Duchenne and Becker muscular dystrophy (DMD/BMD). However, the pathogenicity of complex rearrangements involving DMD , especially segmental duplications with unknown breakpoints, is not well understood. This study aimed to evaluate the structure, pattern, and potential impact of rearrangements involving DMD duplication. Methods Two families with DMD segmental duplications exhibiting phenotypical differences were recruited. Optical genome mapping (OGM) was used to explore the cryptic pattern of the rearrangements. Breakpoints were validated using long-range polymerase chain reaction combined with next-generation sequencing and Sanger sequencing. Results A multi-copy duplication involving exons 64–79 of DMD was identified in Family A without obvious clinical symptoms. Family B exhibited typical DMD neuromuscular manifestations and presented a duplication involving exons 10–13 of DMD . The rearrangement in Family A involved complex in-cis tandem repeats shown by OGM but retained a complete copy (reading frame) of DMD inferred from breakpoint validation. A reversed insertion with a segmental repeat was identified in Family B by OGM, which was predicted to disrupt the normal structure and reading frame of DMD after confirming the breakpoints. Conclusions Validating breakpoint and rearrangement pattern is crucial for the functional annotation and pathogenic classification of genomic structural variations. OGM provides valuable insights into etiological analysis of DMD/BMD and enhances our understanding for cryptic effects of complex rearrangements.

Background Thoracic aortic aneurysm/dissection (TAAD) and patent ductus arteriosus (PDA) are serious autosomal-dominant diseases affecting the cardiovascular system. They are mainly caused by variants in the MYH11 gene, which encodes the heavy chain of myosin 11. The aim of this study was to evaluate the genotype–phenotype correlation of MYH11 from a distinctive perspective based on a pair of monozygotic twins. Methods The detailed phenotypic characteristics of the monozygotic twins from the early fetal stage to the infancy stage were traced and compared with each other and with those of previously documented cases. Whole-exome and Sanger sequencing techniques were used to identify and validate the candidate variants, facilitating the analysis of the genotype–phenotype correlation of MYH11 . Results The monozygotic twins were premature and presented with PDA, pulmonary hypoplasia, and pulmonary hypertension. The proband developed heart and brain abnormalities during the fetal stage and died at 18 days after birth, whereas his sibling was discharged after being cured and developed normally post follow-up. A novel variant c.766 A > G p. (Ile256Val) in MYH11 (NM_002474.2) was identified in the monozygotic twins and classified as a likely pathogenic variant according to the American College of Medical Genetics/Association for Molecular Pathology guidelines. Reviewing the reported cases ( n  = 102) showed that the penetrance of MYH11 was 82.35%, and the most common feature was TAAD (41.18%), followed by PDA (22.55%), compound TAAD and PDA (9.80%), and other vascular abnormalities (8.82%). The constituent ratios of null variants among the cases with TAAD (8.60%), PDA (43.8%), or compound TAAD and PDA (28.6%) were significantly different ( P  = 0.01). Further pairwise comparison of the ratios among these groups showed that there were significant differences between the TAAD and PDA groups ( P  = 0.006). Conclusion This study expands the mutational spectrum of MYH11 and provides new insights into the genotype–phenotype correlation of MYH11 based on the monozygotic twins with variable clinical features and outcomes, indicating that cryptic modifiers and complex mechanisms beside the genetic variants may be involved in the condition.

To examine the overall genomic copy-number variant (CNV) landscape of Chinese pediatric patients with developmental disorders. De-identified chromosomal microarray (CMA) data from 10,026 pediatric patients with developmental disorders were collected for re-evaluating the pathogenic CNV (pCNV) yields of different medical conditions and for comparing the frequency and phenotypic variability of genomic disorders between the Chinese and Western patient populations. The overall yield of pCNVs in the Chinese pediatric patient cohort was 21.37%, with variable yields for different disorders. Yields of pCNVs were positively associated with phenotypic complexity and intellectual disability/developmental delay (ID/DD) comorbidity for most disorders. The genomic burden and pCNV yield in neurodevelopmental disorders supported a female protective effect. However, the stratification analysis revealed that it was seen only in nonsyndromic ID/DD, not in nonsyndromic autism spectrum disorders or seizure. Furthermore, 15 known genomic disorders showed significantly different frequencies in Chinese and Western patient cohorts, and profiles of referred clinical features for 15 known genomic disorders were also significantly different in the two cohorts. We defined the pCNV yields and profiles of the Chinese pediatric patients with different medical conditions and uncovered differences in the frequency and phenotypic diversity of genomic disorders between Chinese and Western patients.

Background Disorders of sex development (DSDs) exhibit high genetic and phenotypic heterogeneity, and genotype–phenotype correlations are not fully understood. 5α-Reductase type 2 (5α-RD2) deficiency, a common form of DSD, is caused by SRD5A2 inactivation. This study investigated the role of SRD5A2 haplotypes in DSD, focusing on their corresponding phenotypes, structural changes and impacts on enzyme activity. Methods This study enrolled 216 individuals with DSD who underwent genetic analysis and 2,794 controls. Linkage disequilibrium analysis was performed in individuals with 5α-RD2 deficiency to identify SRD5A2 haplotypes, and haplotype frequencies were analysed across cohorts. The clinical manifestations of individuals with different SRD5A2 haplotypes were characterized. Structural predictions were employed to investigate the impacts of haplotypes on the 5α-RD2 structure and interactions with ligands. Functionally, kinetic assays were conducted to validate the effects of different haplotypes on enzyme activity. Results A SRD5A2 haplotype composed of c.265C > G and c.680G > A (Hap3: G-A) was identified, and the haplotype frequency was 64.71% in individuals with 5α-RD2 deficiency, 2.59% and 1.22% in non-5α-RD2 deficiency DSD cases without or with known DSD-related gene variants, respectively, and 1.57% in in-house controls. Globally, Hap3: G-A was enriched in southern Chinese individuals and showed high population differentiation, indicating a potential founder effect of the haplotype. The majority of homozygotes of Hap3: G-A presented microphallus, and nearly half of them manifested isolated microphallus. Structurally, Hap3: G-A was predicted to result in an increase in the solvent-accessible surface area (10.72 Å 2 ), a redistribution of hydrogen bonds within 5α-RD2, and a loss of key hydrogen bonds with NADPH. Functionally, kinetic assays showed that the catalytic efficiency of the enzyme encoded by Hap3: G-A was between that of Hap1: G-G and that of Hap2: C-A. Conclusions Hap3: G-A, which is prevalent in individuals with 5α-RD2 deficiency, suggests a potential founder effect. Structurally, compared with other haplotypes, Hap3: G-A seems to have a combined effect on the structure and interaction of 5α-RD2, rather than have merely additive effects of its constituent variants. Functionally, kinetic assays suggested a hypomorphic effect of Hap3: G-A. These findings provide valuable insights for understanding genotype–phenotype correlations, genetic counselling, early intervention and clinical management of individuals with 5α-RD2 deficiency or even other DSDs. Highlights On the basis of 216 DSD individuals and 2,794 controls, a novel SRD5A2 haplotype (Hap3: G-A), which is composed of common variants and is especially prevalent in DSD patients with 5α-RD2 deficiency, was identified, indicating the potential founder effect of Hap3: G-A. The majority of 5α-RD2 deficiency individuals with homozygous Hap3: G-A presented microphallus. Three-dimensional structure and model construction predicted that Hap3: G-A resulted in an increase in the solvent-accessible surface area, redistribution of hydrogen bonds within 5α-RD2, and loss of key hydrogen bonds with NADPH. Functionally, kinetic assays showed that the catalytic efficiency of the enzyme encoded by Hap3: G-A was between those of Hap1: G-G and Hap2: C-A, suggesting a hypomorphic effect of this haplotype. Plain Language Summary Individuals with disorders of sex development (DSDs) present variable genotypes and phenotypes, and the genotype–phenotype correlation remains poorly understood. 5α-Reductase type 2 (5α-RD2) deficiency, a common form of DSD, is caused by SRD5A2 inactivation. In this study, genetic testing and analysis were performed in 216 individuals with DSD and 2,794 non-DSD controls. A novel SRD5A2 haplotype (Hap3: G-A) was identified, and the haplotype frequency was 64.71% in individuals with 5α-RD2 deficiency, 2.59% and 1.22% in non-5α-RD2 deficiency DSD cases without or with known DSD-related gene variants, respectively, and 1.57% in in-house controls. Globally, Hap3: G-A was enriched in southern Chinese individuals and showed high population differentiation, indicating a potential founder effect of the haplotype. Analyzing the phenotype spectrum of individuals with 5α-RD2 deficiency, we found that the majority of homozygotes of Hap3: G-A presented microphallus, and nearly half of them manifested isolated microphallus. Structurally, Hap3: G-A was predicted to result in an increase in the solvent-accessible surface area, the redistribution of hydrogen bonds within 5α-RD2, and the loss of key hydrogen bonds with NADPH. Compared with other haplotypes, Hap3: G-A seemed to have a combined effect on the structure and interaction of 5α-RD2, rather than simply additive effects of its constituent variants. Functionally, kinetic assays showed that the catalytic efficiency of the enzyme encoded by Hap3: G-A was between that of Hap1: G-G and that of Hap2: C-A, suggesting a hypomorphic effect of this haplotype. These findings provide valuable insights for understanding genotype–phenotype correlations, genetic counselling, early intervention and clinical management of individuals with 5α-RD2 deficiency or even other DSDs.

ROR2, a member of the ROR family, is essential for skeletal development as a receptor of Wnt5a. The present study aims to investigate the mutational spectrum of in children with short stature and to identify the underlying molecular mechanisms. We retrospectively analyzed clinical phenotype and whole-exome sequencing (WES) data of 426 patients with short stature through mutation screening of . We subsequently examined the changes in protein expression and subcellular location in caused by the mutations. The mRNA expression of downstream signaling molecules of the Wnt5a-ROR2 pathway was also examined. We identified 12 mutations in in 21 patients, including 10 missense, one nonsense, and one frameshift. Among all missense variants, four recurrent missense variants [c.1675G > A(p.Gly559Ser), c.2212C > T(p.Arg738Cys), c.1930G > A(p.Asp644Asn), c.2117G > A(p.Arg706Gln)] were analyzed by experiments . The c.1675G > A mutation significantly altered the expression and the cellular localization of the ROR2 protein. The c.1675G > A mutation also caused a significantly decreased expression of c-Jun. In contrast, other missense variants did not confer any disruptive effect on the biological functions of ROR2. We expanded the mutational spectrum of in patients with short stature. Functional experiments potentially revealed a novel molecular mechanism that the c.1675G > A mutation in might affect the expression of downstream Wnt5a-ROR2 pathway gene by disturbing the subcellular localization and expression of the protein.

Background Nocamycins I and II, produced by the rare actinomycete Saccharothrix syringae , belong to the tetramic acid family natural products. Nocamycins show potent antimicrobial activity and they hold great potential for antibacterial agent design. However, up to now, little is known about the exact biosynthetic mechanism of nocamycin. Results In this report, we identified the gene cluster responsible for nocamycin biosynthesis from S. syringae and generated new nocamycin derivatives by manipulating its gene cluster. The biosynthetic gene cluster for nocamycin contains a 61 kb DNA locus, consisting of 21 open reading frames (ORFs). Five type I polyketide synthases (NcmAI, NcmAII, NcmAIII, NcmAIV, NcmAV) and a non-ribosomal peptide synthetase (NcmB) are proposed to be involved in synthesis of the backbone structure, a Dieckmann cyclase NcmC catalyze the releasing of linear chain and the formation of tetramic acid moiety, five enzymes (NcmEDGOP) are related to post-tailoring steps, and five enzymes (NcmNJKIM) function as regulators. Targeted inactivation of ncmB led to nocamycin production being completely abolished, which demonstrates that this gene cluster is involved in nocamycin biosynthesis. To generate new nocamycin derivatives, the gene ncmG , encoding for a cytochrome P450 oxidase, was inactivated. Two new nocamycin derivatives nocamycin III and nocamycin IV were isolated from the ncmG deletion mutant strain and their structures were elucidated by spectroscopic data analyses. Based on bioinformatics analysis and new derivatives isolated from gene inactivation mutant strains, a biosynthetic pathway of nocamycins was proposed. Conclusion These findings provide the basis for further understanding of nocamycin biosynthetic mechanism, and set the stage to rationally engineer new nocamycin derivatives via combinatorial biosynthesis strategy.

The chloromethyl-functionalized polystyrene is the most commonly used ammonium cation precursor for making anion exchange resins (AER) and membranes (AEM). However, the chloromethylation of polystyrene or styrene involves highly toxic and carcinogenic raw materials (e.g., chloromethyl ether) and the resultant ammonium cation structural motif is not stable enough in alkaline media. Herein, we present a novel self-pored amine-functionalized polystyrene, which may provide a safe, convenient, and green process to make polystyrene-based AER and AEM. It is realized by hydrolysis of the copolymer obtained via random copolymerization of N-vinylformamide (NVF) with styrene (St). The composition and structure of the NVF-St copolymer could be controlled by monomeric ratio, and the copolymers with high NVF content could form bicontinuous morphology at sub-100 nm levels. Such bicontinuous morphology allows the copolymers to be swollen in water and self-pored by freeze-drying, yielding a large specific surface area. Thus, the copolymer exhibits high adsorption capacity (226 mg/g for bisphenol A). Further, the amine-functionalized polystyrene has all-carbon backbone and hydrophilic/hydrophobic microphase separation morphology. It can be quaternized to produce ammonium cations and would be an excellent precursor for making AEM and AER with good alkaline stability and smooth ion transport channels. Therefore, the present strategy may open a new pathway to develop porous alkaline stable AER and AEM without using metal catalysts, organic pore-forming agents, and carcinogenic raw materials.

Silicon-based neural microneedle arrays, such as the Utah Array, have demonstrated excellent performance in chronic recordings from the cerebral cortex. Unlike planar thin-film electrodes with recording sites arranged on the surface of a silicon film, the recording sites of microneedle arrays are located at the tips of three-dimensional needles, which significantly complicates the fabrication process required for single-neuron recordings. To address this challenge, we develop a local de-insulation method for microneedle recording electrodes that eliminates the need for etching: the microneedle tips are encapsulated in a controllable-thickness protective layer, followed by deposition of a Parylene-C insulation layer. By optimizing the elasticity of the protection material, as well as its adhesion and shape on both the protective layer and the electrode shaft, we were able to precisely control the area of the removed insulated layers, resulting in consistent tip exposure. Experimental results show that the non-uniformity of the exposed microneedle recording sites in the silicon-based neural microelectrode arrays (each has 10 × 10 array) fabricated using this method is 3.32 ± 1.02%. Furthermore, the arrays exhibited high stability and reliability in both mechanical performance and electrical characteristics. They achieved an average spike signal-to-noise ratio of 12.63 ± 6.64 during in vivo testing. This fabrication technique provides a valuable method for the development of high-performance neural microelectrode array.