Primary ciliary dyskinesia (PCD) is a clinically rare, genetically and phenotypically heterogeneous condition characterized by chronic respiratory tract infections, male infertility, tympanitis, and laterality abnormalities. PCD is typically resulted from variants in genes encoding assembly or structural proteins that are indispensable for the movement of motile cilia. Here, we identified a novel nonsense mutation, c.466G>T, in cilia- and flagella-associated protein 300 ( CFAP300 ) resulting in a stop codon (p.Glu156*) through whole-exome sequencing (WES). The proband had a PCD phenotype with laterality defects and immotile sperm flagella displaying a combined loss of the inner dynein arm (IDA) and outer dynein arm (ODA). Bioinformatic programs predicted that the mutation is deleterious. Successful pregnancy was achieved through intracytoplasmic sperm injection (ICSI). Our results expand the spectrum of CFAP300 variants in PCD and provide reproductive guidance for infertile couples suffering from PCD caused by them.
Adult ; Female ; Humans ; Male ; Pregnancy ; China ; Ciliary Motility Disorders/genetics* ; Codon, Nonsense ; East Asian People/genetics* ; Exome Sequencing ; Homozygote ; Infertility, Male/genetics* ; Kartagener Syndrome/genetics* ; Pedigree ; Sperm Injections, Intracytoplasmic ; Cytoskeletal Proteins/genetics*

OBJECTIVE: To analyze the correlation between variants in the start codon of the α-globin gene and phenotypes of thalassemia, so as to provide a basis for the diagnosis and prevention of α-thalassemia. METHODS: A retrospective study was conducted on 7 patients diagnosed by Yangjiang People's Hospital and Guangzhou Hybribio Co. Ltd., from June 2019 to October 2022. Routine blood tests and hemoglobin electrophoresis were carried out. Potential variants were identified through polymerase chain reaction (PCR) combined with Reverse dot blotting (RDB), Gap-PCR, and Sanger sequencing. This study has been approved by the Medical Ethics Committee of People's Hospital of Yangjiang (Ethics No: 20240001). RESULTS: For the 7 patients, results of blood routine test of one case was unknown, and that of another was normal. The remaining 5 cases had presented with microcytic hypochromic anemia. The results of hemoglobin electrophoresis showed that one case had normal Hb A and slightly lower Hb A2, whilst another had significantly decreased Hb A and Hb A2, in addition with the appearance of a Hb H band. The content of Hb Bart's in four neonates was ≥ 0.4%. The remaining one case had no result. Genetic testing has identified 4 rare start codon mutations, namely HBA2: c.2delT, HBA2: c.1A>G, HBA2: c.1A>T, and HBA1: c.2T>C. Among these, Patient 1 had harbored compound heterozygous variants of HBA2: c.427T>C (Hb CS) and HBA2: c.2delT. Patient 4 had harbored compound heterozygous variants of HBA2: c.1A>G and Southeast Asian type deletion. CONCLUSION Heterozygotes with HBA start codon variants usually present as silent or mild thalassemia, and the symptoms of anemia may deteriorate when combined with other α-thalassemia variant. The HBA2: c.1A>T start codon variant was unreported previously in China. The detection of start codon variants has helped to clarify the causes of anemia, genetic counseling, and guidance for reproduction.
Humans ; Phenotype ; Codon, Initiator/genetics* ; Female ; Male ; Retrospective Studies ; alpha-Globins/genetics* ; alpha-Thalassemia/genetics* ; Hemoglobin A/genetics* ; Adult ; Mutation

OBJECTIVE: To explore the genotype-phenotype relationship in a child with Opitz G/BBB syndrome (OS) with mild clinical phenotype. METHODS: A child with motor developmental delay as the initial symptom admitted to Xi'an Children's Hospital on June 10, 2021 was selected for this study. Clinical data were collected, and peripheral blood samples were obtained from the child and his mother. Whole exome sequencing (WES) was performed to identify genetic variant in the child. Candidate variant were verified by Sanger sequencing to assess inheritance patterns and pathogenicity. Real-time fluorescence quantitative PCR (RT-qPCR) and Western blot (WB) analyses were conducted to evaluate the effects of the variant on mRNA and protein expression, respectively, using recombinant expression plasmids generated in vitro. This study was approved by the Medical Ethics Committee of Xi'an Children's Hospital (Ethics No. 20240045). RESULTS: The child, a 9-month-and-7-day-old boy, presented with a low nasal bridge, hypertelorism, and difficulty sitting independently. Echocardiography revealed an atrial septal defect. WES identified a homozygous variant in the MIDI gene, c.1483C>T (p.R495X), which was confirmed by Sanger sequencing and found to be inherited from the mother.Recombinant expression plasmids were successfully constructed. RT-qPCR analysis showed that the variant significantly reduced MIDI gene mRNA expression, while WB results indicated that the variant led to the production of a truncated protein. CONCLUSION The mild clinical phenotype of OS in this child may be attributed to the mRNA degradation escape mechanism induced by the nonsense variant c.1483C>T (p.R495X) in the MIDI gene. These findings provide valuable diagnostic insights for this pedigree and contribute to the understanding of the genotype-phenotype correlation in OS.
Humans ; Male ; Infant ; Transcription Factors/metabolism* ; Microtubule Proteins/genetics* ; Craniosynostoses/genetics* ; Hypospadias/genetics* ; Codon, Nonsense/genetics* ; RNA, Messenger/metabolism* ; Female ; RNA Stability/genetics* ; Phenotype ; Nuclear Proteins/genetics* ; Ubiquitin-Protein Ligases ; Esophagus/abnormalities* ; Hypertelorism

OBJECTIVE: To carry out pathological and genetic analyses on a fetus with intrauterine growth restriction and death during second trimester after induced abortion. METHODS: A fetus undergone induced abortion due to intrauterine growth restriction and death during second trimester at the the Seventh Affiliated Hospital of Sun Yat-Sen University in 2024 was selected as the study subject. Clinical data of the pregnancy were collected. DNA was extracted from tissues from the aborted fetus and peripheral blood samples from its parents. Chromosomal microarray analysis and whole exome sequencing were carried out. Candidate variants were verified by Sanger sequencing. Following abortion, routine autopsy and pathological analysis were conducted. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: KY-2025-334-01). RESULTS: The aborted fetus was a male and harbored compound heterozygous nonsense variants of the TH gene (c.457C>T/p.Arg153* and c.694C>T/p.Gln232*), for which both parents were heterozygous carriers. Autopsy and pathological analysis revealed that the fetus had pathological features including loose arrangement of myocardial fibers and congestion in the liver. CONCLUSION Biallelic null variants of the TH gene may cause heart failure by affecting the development of cardiovascular system, which in turn may lead to intrauterine death. This study has provided new clues for the molecular diagnosis of stillbirth and recurrent pregnancy loss.
Humans ; Female ; Pregnancy ; Male ; Heterozygote ; Codon, Nonsense/genetics* ; Fetal Growth Retardation/pathology* ; Adult ; Stillbirth/genetics*

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system, belonging to the type II CRISPR/Cas system, is an effective gene-editing tool widely used in different organisms, but the size of Streptococcus pyogenes Cas9 (SpCas9) is quite large (4.3 kb), which is not convenient for vector delivery. In this study, we used a codon-optimized Staphylococcus aureus Cas9 (SaCas9) system to edit the tyrosinase (tyr), oculocutaneous albinism II (oca2), and paired box 6.1 (pax6.1) genes in the fish model medaka(Oryzias latipes), in which the size of SaCas9 (3.3 kb) is much smaller and the necessary protospacer-adjacent motif (PAM) sequence is 5'-NNGRRT-3'. We also used a transfer RNA (tRNA)‍-single-guide RNA (sgRNA) system to express the functional sgRNA by transcription eitherin vivo or in vitro, and the combination of SaCas9 and tRNA-sgRNA was used to edit the tyr gene in the medaka genome. The SaCas9/sgRNA and SaCas9/tRNA-sgRNA systems were shown to edit the medaka genome effectively, while the PAM sequence is an essential part for the efficiency of editing. Besides, tRNA can improve the flexibility of the system by enabling the sgRNA to be controlled by a common promoter such as cytomegalovirus. Moreover, the all-in-one cassette cytomegalovirus (CMV)‍-SaCas9-tRNA-sgRNA-tRNA is functional in medaka gene editing. Taken together, the codon-optimized SaCas9 system provides an alternative and smaller tool to edit the medaka genome and potentially other fish genomes.
Animals ; Oryzias/genetics* ; Gene Editing/methods* ; CRISPR-Cas Systems ; Codon ; RNA, Guide, CRISPR-Cas Systems/genetics* ; Monophenol Monooxygenase/genetics* ; CRISPR-Associated Protein 9/genetics* ; RNA, Transfer/genetics* ; Staphylococcus aureus/genetics* ; PAX6 Transcription Factor/genetics*

The variable domain of heavy-chain antibody (VHH) has been developed widely in drug therapy, diagnosis, and research. Escherichia coli is the most popular expression system for VHH production, whereas low bioactivity occurs sometimes. Mammalian cells are one of the most ideal hosts for VHH expression at present. To improve the yield of VHH in Expi293F cells, we optimized the signal peptide (SP) and codons of VHH. Firstly, the fusion protein VHH1-Fc was used to screen SPs. The SP IFN-α2 showed the highest secretion as quantified by enzyme-linked immunosorbent assay (ELISA). Subsequently, codon optimization by improving GC3 and GC content doubled the yield of VHH1 and kept its binding activity to Senecavirus A (SVA). Finally, the mean yields of other 5 VHHs that fused with SP IFN-α2 and codon-optimized were over 191.6 mg/L, and these VHHs had high recovery and high purity in the culture supernatant. This study confirms that SP IFN-α2 and codon optimization could produce VHHs in Expi293F cells efficiently, which provides a reference for the large-scale production of VHHs.
Codon/genetics* ; Protein Sorting Signals/genetics* ; Escherichia coli/metabolism* ; Humans ; Recombinant Fusion Proteins/biosynthesis* ; Interferon-alpha/metabolism* ; Immunoglobulin Heavy Chains/immunology* ; Cell Line ; Immunoglobulin Variable Region/immunology*

The structure and size of the chloroplast genome of Castanopsis hystrix was determined by Illumina HiSeq 2500 sequencing platform to understand the difference between C. hystrix and the chloroplast genome of the same genus, and the evolutionary position of C. hystrix in the genus, so as to facilitate species identification, genetic diversity analysis and resource conservation of the genus. Bioinformatics analysis was used to perform sequence assembly, annotation and characteristic analysis. R, Python, MISA, CodonW and MEGA 6 bioinformatics software were used to analyze the genome structure and number, codon bias, sequence repeats, simple sequence repeat (SSR) loci and phylogeny. The genome size of C. hystrix chloroplast was 153 754 bp, showing tetrad structure. A total of 130 genes were identified, including 85 coding genes, 37 tRNA genes and 8 rRNA genes. According to codon bias analysis, the average number of effective codons was 55.5, indicating that the codons were highly random and low in bias. Forty-five repeats and 111 SSR loci were detected by SSR and long repeat fragment analysis. Compared with the related species, chloroplast genome sequences were highly conserved, especially the protein coding sequences. Phylogenetic analysis showed that C. hystrix is closely related to the Hainanese cone. In summary, we obtained the basic information and phylogenetic position of the chloroplast genome of red cone, which will provide a preliminary basis for species identification, genetic diversity of natural populations and functional genomics research of C. hystrix.
Phylogeny ; Genome, Chloroplast ; Codon/genetics* ; Genomics ; Chloroplasts/genetics*

Pellionia scabra belongs to the genus Pellionia in the family of Urticaceae, and is a high-quality wild vegetables with high nutritional value. In this study, high-throughput techniques were used to sequence, assemble and annotate the chloroplast genome. We also analyzed its structure, and construct the phylogenetic trees from the P. scabra to further study the chloroplast genome characteristics. The results showed that the chloroplast genome size was 153 220 bp, and the GC content was 36.4%, which belonged to the typical tetrad structure in P. scabra. The chloroplast genome encodes 130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes in P. scabra. Among them, 15 genes contained 1 intron, 2 genes contained 2 introns, and rps12 had trans-splicing, respectively. In P. scabra, chloroplast genomes could be divided into four categories, including 43 photosynthesis, 64 self-replication, other 7 coding proteins, and 4 unknown functions. A total of 51 073 codons were detected in the chloroplast genome, among which the codon encoding leucine (Leu) accounted for the largest proportion, and the codon preferred to use A and U bases. There were 72 simple sequence repeats (SSRs) in the chloroplast genome of P. scabra, containing 58 single nucleotides, 12 dinucleotides, 1 trinucleotide, and 1 tetranucleotide. The ycf1 gene expansion was present at the IRb/SSC boundary. The phylogenetic trees showed that P. scabra (OL800583) was most closely related to Elatostema stewardii (MZ292972), Elatostema dissectum (MK227819) and Elatostema laevissimum var. laevissimum (MN189961). Taken together, our results provide worthwhile information for understanding the identification, genetic evolution, and genomics research of P. scabra species.
Phylogeny ; Genome, Chloroplast/genetics* ; Genomics ; Chloroplasts/genetics* ; Codon ; Urticaceae/genetics*

The genomic DNA of Rubus rosaefolius was extracted and sequenced by Illumina NovaSeq platform to obtain the complete chloroplast genome sequence, and the sequence characteristics and phylogenetic analysis of chloroplast genes were carried out. The results showed that the complete chloroplast genome of the R. rosaefolius was 155 650 bp in length and had a typical tetrad structure, including two reverse repeats (25 748 bp each), a large copy region (85 443 bp) and a small copy region (18 711 bp). A total of 131 genes were identified in the whole genome of R. rosaefolius chloroplast, including 86 protein coding genes, 37 tRNA genes and 8 rRNA genes. The GC content of the whole genome was 36.9%. The genome of R. rosaefolius chloroplast contains 47 scattered repeats and 72 simple sequence repeating (SSR) loci. The codon preference is leucine codon, and the codon at the end of A/U is preferred. Phylogenetic analysis showed that R. rosaefolius had the closest relationship with R. taiwanicola, followed by R. rubraangustifolius and R. glandulosopunctatus. The chloroplast genome characteristics and phylogenetic analysis of R. rosaefolius provide a theoretical basis for its genetic diversity research and chloroplast development and utilization.
Phylogeny ; Rubus/genetics* ; Genome, Chloroplast ; Fruit/genetics* ; Codon/genetics*

OBJECTIVE: To explore the clinical characteristics and genetic etiology of a consanguineous Chinese pedigree affected with Congenital coagulation factor XII (XII) deficiency. METHODS: Members of the pedigree who had visited Ruian People's Hospital on July 12, 2021 were selected as the study subjects. Clinical data of the pedigree were reviewed. Peripheral venous blood samples were taken from the subjects. Blood coagulation index and genetic testing were carried out. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: This pedigree has comprised 6 individuals from 3 generations, including the proband, his father, mother, wife, sister and son. The proband was a 51-year-old male with kidney stones. Blood coagulation test showed that his activated partial thromboplastin time (APTT) was significantly prolonged, whilst the FXII activity (FXII:C) and FXII antigen (FXII:Ag) were extremely reduced. The FXII:C and FXII:Ag of proband's father, mother, sister and son have all reduced to about half of the lower limit of reference range. Genetic testing revealed that the proband has harbored homozygous missense variant of c.1A>G (p.Arg2Tyr) of the start codon in exon 1 of the F12 gene. Sanger sequencing confirmed that his father, mother, sister and son were all heterozygous for the variant, whilst his wife was of the wild type. By bioinformatic analysis, the variant has not been included in the HGMD database. Prediction with SIFT online software suggested the variant is harmful. Simulation with Swiss-Pbd Viewer v4.0.1 software suggested that the variant has a great impact on the structure of FXII protein. Based on the Standards and Guidelines for the Interpretation of Sequence Variants: A Joint Consensus Recommendation of the American College of Medical Genetics and Genomics (ACMG), the variant was rated as likely pathogenic. CONCLUSION The c.1A>G (p.Arg2Tyr) variant of the F12 gene probably underlay the Congenital FXII deficiency in this pedigree. Above finding has further expanded the spectrum of F12 gene variants and provided a reference for clinical diagnosis and genetic counseling for this pedigree.
Male ; Female ; Humans ; Middle Aged ; Factor XII/genetics* ; Pedigree ; Codon, Initiator ; East Asian People ; Mothers ; Factor XII Deficiency/genetics* ; Mutation