OBJECTIVE: To analyze the B_el subtype gene mutation and its genetic mechanism in a family line. METHODS: ABO blood groups were identified by serologic tests. ABO genotyping was performed by polymerase chain reaction with sequence-specific primer (PCR-SSP). Sanger sequencing was performed on exons 1-7 of the ABO gene, the flanking intronic region, and exon 7 of the single strand of the gene confirmed the mutation site location. Missense3D software was used to predict the protein structure alteration caused by this mutation. RESULTS: Conventional serologic tests failed to detect erythrocyte B antigen in the proband and her three family members, and only trace amounts of B antigen expression could be detected by the absorption-dispersal test. DNA analysis showed that, on the basis of the normal ABO gene, there was a G>T substitution in the position of exon 7, position 803, which resulted in the change of amino acid 268 from Gly to Val. Further single-stranded sequencing analysis showed that the mutation site was located in the B gene. CONCLUSION In this family line, the proband, her father, her son, and her daughter all have reduced B type glycosyltransferase activity due to the new point mutation (c.803G>T) in exon 7 of the B gene, and the B antigen can only be detected by the absorption-dispersal method, and the point mutation can be stably inherited by offspring.
Point Mutation ; Alleles ; ABO Blood-Group System/genetics* ; Exons ; Introns ; Genotype ; Humans ; Male ; Female ; Glycosyltransferases/genetics*

OBJECTIVE: To explore the laboratory phenotype and molecular pathogenesis in a Chinese pedigree affected with Hereditary coagulation factor Ⅻ (FⅫ) deficiency. METHODS: A male proband admitted to Ningbo No.2 Hospital on July 17, 2021 due to chronic gastritis and members of his pedigree (7 individuals from three generations) were selected as the study subjects. Prothrombin time (PT), activated partial thromboplastin time (APTT), FⅧ activity (FⅧ: C), FⅨ activity (FⅨ: C), FⅪ activity (FⅪ: C), FⅫ activity (FⅫ: C), and FⅫ antigen (FⅫ: Ag) were determined. All of the exons, exon-intronic boundaries, as well as the 5'- and 3'-untranslated regions of the F12 gene were subjected to Sanger sequencing. Candidate variants were verified by cloning sequencing. The effect of candidate variants on the protein function was analyzed by bioinformatics software. RESULTS: The proband, a 47-year-old male, had significantly prolonged APTT (180.0 s) and decreased FⅫ:C and FⅫ:Ag levels (< 1%). His father, mother, brother and two sons also showed certain degrees of reduction. Genetic testing revealed that the proband has harbored compound heterozygous variants of the F12 gene, namely c.1092_1093insC (p.Lys365Glnfs*69) in exon 10 and c.1792_1796delGTCTA (p.Val579Hisfs*32) in exon 14. His mother and elder son were heterozygous for the c.1092_1093ins variant, whilst his father, brother, and younger son were heterozygous for the c.1792_1796delGTCTA variant. Analysis of the promoter region of exon 1 also showed that the proband and both sons had harbored a 46T/T polymorphism, whilst other family members were 46C/T. Bioinformatic analysis suggested that the p.Val579 is a highly conserved site. Protein model analysis showed that, with the p.Val579Hisfs*32 variant, a benzene ring was added and the hydrogen bond of surrounding amino acids was changed. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.1792_1796delGTCTA was classified as a pathogenic variant (PVS1+PM2_Supporting+PM4). CONCLUSION The c.1092_1093insC (p.Lys365Glnfs*69) and c.1792_1796delGTCTA (p.Val579Hisfs*32) compound heterozygous variants of the F12 gene probably underlay the decreased FXII levels in this pedigree. Above finding has also enriched the mutational spectrum for FⅫ deficiency.
Male ; Humans ; Aged ; Middle Aged ; Pedigree ; East Asian People ; Exons ; Introns ; Family ; Factor XII Deficiency/genetics* ; 3' Untranslated Regions ; Factor XII/genetics*

OBJECTIVE: To explore the genetic etiology for a Chinese pedigree affected with Lesch-Nyhan syndrome. METHODS: Members of the pedigree who had visited the Genetic Counseling Clinic of Linyi People's Hospital on February 10, 2022 were selected as the study subjects. Clinical data and family history of the proband were collected, and trio-whole exome sequencing (trio-WES) was carried out for the proband and his parents. Candidate variants were verified by Sanger sequencing. RESULTS: Trio-WES revealed that both the proband and his cousin brother had harbored a hemizygous c.385-1G>C variant in intron 4 of the HPRT1 gene, which was unreported previously. A heterozygous c.385-1G>C variant of the HPRT1 gene was also found in the proband's mother, grandmother, two aunts, and a female cousin, whilst all phenotypically normal males in his pedigree were found to have a wild type for the locus, which has conformed to an X-linked recessive inheritance. CONCLUSION The heterozygous c.385-1G>C variant of the HPRT1 gene probably underlay the Lesch-Nyhan syndrome in this pedigree.
Male ; Humans ; Female ; Lesch-Nyhan Syndrome/genetics* ; Pedigree ; East Asian People ; Heterozygote ; Introns ; Mutation

Emerging evidence suggests that intron-detaining transcripts (IDTs) are a nucleus-detained and polyadenylated mRNA pool for cell to quickly and effectively respond to environmental stimuli and stress. However, the underlying mechanisms of detained intron (DI) splicing are still largely unknown. Here, we suggest that post-transcriptional DI splicing is paused at the Bact state, an active spliceosome but not catalytically primed, which depends on Smad Nuclear Interacting Protein 1 (SNIP1) and RNPS1 (a serine-rich RNA binding protein) interaction. RNPS1 and Bact components preferentially dock at DIs and the RNPS1 docking is sufficient to trigger spliceosome pausing. Haploinsufficiency of Snip1 attenuates neurodegeneration and globally rescues IDT accumulation caused by a previously reported mutant U2 snRNA, a basal spliceosomal component. Snip1 conditional knockout in the cerebellum decreases DI splicing efficiency and causes neurodegeneration. Therefore, we suggest that SNIP1 and RNPS1 form a molecular brake to promote spliceosome pausing, and that its misregulation contributes to neurodegeneration.
Spliceosomes/metabolism* ; Introns/genetics* ; RNA Splicing ; RNA, Messenger/genetics* ; Cell Nucleus/metabolism*

OBJECTIVE: To investigate the relationship between the type of FⅧgene mutation and the development of FⅧ inhibitors in patients with severe haemophilia A (HA). METHODS: The medical records of 172 patients with severe hemophilia A from January 2009 to September 2020 were reviewed. The types of FⅧgene mutations and the production of factor Ⅷ inhibitors were collected and divided into high-risk mutation group ( intron 1 inversions, large deletions, nonsense mutations), low-risk mutation group (missense mutations, small deletions and insertions, splice site mutations) and intron 22 inversions group. The correlation of FⅧgenotype and the production of FⅧ inhibitors in patients with HA were analyzed. RESULTS: Among 172 patients with severe HA, 21 cases(12.21%) developed FⅧ inhibitors. The cumulative incidence of FⅧ inhibitor development was 32%(10/31) in high risk group (75% patients with large deletions, 43% patients with intron 1 inversions, 20% patients with nonsense mutations) and 5%(2/43) in low risk group(6% patients with missense mutations, 5% patients with small deletions or insertions and 0% patient with a splice site mutation) and 9%(9/98) in intron 22 inversions group. Compared with the risk of FⅧ inhibitor development in intron 22 inversions group, the risk of FⅧ inhibitor development in high risk group was higher (OR＝4.7, 95% CI： 1.7-13.0), the risk of FⅧ inhibitor development in low risk group was equal (OR＝0.5, 95% CI： 0.1-2.3). Compared with the risk of inhibitor development in low risk group, the risk of FⅧ inhibitor development in high risk group was higher (OR＝9.8, 95% CI： 2.0-48.7). CONCLUSION Gene mutations of patients with severe HA in high-risk group which include intron 1 inversions, large deletions, nonsense mutations are a risk factor for FⅧ inhibitor production.
Codon, Nonsense ; DNA Mutational Analysis ; Factor VIII/genetics* ; Hemophilia A/genetics* ; Humans ; Introns ; Mutation

Group Ⅱ introns are self-splicing ribozymes, which insert directly into target sites in DNA with high frequency through "retrohoming". They specifically and efficiently recognize and splice DNA target sites, endowing themselves with great potential in genetic engineering. This paper reviewed the gene targeting principle of group Ⅱ introns and the application in microbial genetic modification, and then analyzed the limitations of them in multi-functional gene editing and eukaryotes based on the "retrohoming" characteristics and the dependence on high Mg²⁺ concentration. Finally, we dissected the potential of group Ⅱ introns in the development of novel gene editing tools based on our previous research outcome and the structural characteristics of the introns, hoping to provide a reference for the application of group Ⅱ introns in biotechnology.
DNA ; Eukaryota ; Gene Targeting ; Introns/genetics* ; RNA, Catalytic/genetics*

OBJECTIVE: To report on a case with severe hemophilia A (HA) due to a large duplication of F8 gene. METHODS: Inversion detection, Sanger sequencing, and multiplex ligation-dependent probe amplification (MLPA) were used to detect the mutation in the proband and his mother. RESULTS: The patient, a 7-year-old boy, was diagnosed with severe HA at 8 months. No inhibitor was developed over 150 exposure days. Intronic inversion detection and Sanger sequencing have failed to identify pathogenic variants, while MLPA revealed a large duplication [Ex 1_22 dup (2 copies)] in the proband, for which his mother was a carrier [Ex 1_22 dup (3 copies)]. Large duplications of the F8 gene have so far been found in 24 HA patients, all of whom had a severe phenotype, only one had a history of inhibitors. CONCLUSION Large duplications of F8 gene are associated with severe HA. The diagnostic rate for HA may be increased by MLPA.
Child ; Factor VIII/genetics* ; Gene Duplication ; Hemophilia A/genetics* ; Humans ; Introns ; Male ; Mutation ; Phenotype

OBJECTIVE: To detect pathogenic variant in a child featuring Usher syndrome type II. METHODS: Peripheral blood samples of the child and his parents were collected for the analysis of variants of hearing impairment-related genes. The findings were verified in 100 individuals with normal hearing. RESULTS: The child was found to harbor compound heterozygous variants of the USH2A gene, namely c.8224-1G>C in intron 41 and c.5678C>G(p.Ser1893X) in exon 28, which were inherited respectively from his mother and father. Based on the American College of Medical Genetics and Genomics standards and guidelines, both c.8224-1G>C and c.5678C>G(p.Ser1893X) variants of USH2A gene were predicted to be pathogenic(PVS1+PM2+PM3). CONCLUSION The compound heterozygous variants c.8224-1G>C and c.5678C>G of the USH2A gene probably underlay the disease in this child. Above finding has enriched the spectrum of USH2A gene variants.
Child ; Exons ; Extracellular Matrix Proteins/genetics* ; Family ; Humans ; Introns ; United States ; Usher Syndromes/genetics*

Estrogen receptor (esr) mediates the effects of estrogen on the expression of related genes, thereby regulating the growth and reproduction of mammals. To investigate the effect of retrotransposon insertion polymorphism (RIP) of the porcine esr gene on porcine growth performance, retrotransposon insertion polymorphism of the esr gene were predicted by comparative genomics and bioinformatics, and PCR was used to verify the insertion polymorphisms in different porcine breeds. Finally, the correlation analysis between the genotypes and performance of Large White pigs was conducted. The results showed that four retrotransposon polymorphic sites were identified in the esr1 and esr2 genes, which are esr1-SINE- RIP1 located in intron 2 of the esr1 gene, esr1-LINE-RIP2 and RIP3-esr1- SINE located in intron 5 of the gene, and esr2-LINE-RIP located in intron 1 of the esr2 gene, respectively. Among them, insertion of a 287 bp of SINE into intron 2 of the esr1 gene significantly affected (P<0.05) the live back fat thickness and 100 kg body weight back fat thickness of Large White pigs. Moreover, the live back fat thickness and back fat thickness at 100 kg body weight of homozygous with insertion (SINE+/+) was significantly greater than that of heterozygous with insertion (SINE+/-) and homozygous without insertion (SINE-/-). Therefore, esr1-SINE-RIP1 could be used as a molecular marker to assist the selection of deposition traits in Large White pigs.
Animals ; Genotype ; Introns/genetics* ; Phenotype ; Polymorphism, Genetic/genetics* ; Retroelements/genetics* ; Swine/genetics*

OBJECTIVE: To explore the molecular mechanism of a case where RhD genotyping did not match serological results. METHODS: The serological results of 8 members from two generations of this family were analyzed. And according to Mendelian law of inheritance, RhD genotyping, zygotic type determination and gene sequencing were performed for the family members. RESULTS: The proband and one of her cousins have the same RhD alleles, both of them have a 336-1G>A intron variant RhD allele and a complete RhD deletion allele. The variant alleles are inherited from two of their parents with blood relationship, while the complete-deleted alleles come from the other. 336-1G>A means that the last base G of the second intron of the RhD gene is mutated to A, which leads to a negative RhD serology and a positive genotype in the proband. CONCLUSION There was a rare 336-1G> A intron variant gene (RhD * 01N.25) in this family, which was a recessive gene relative to the RhD gene and resulted in RhD phenotype negative.
Alleles ; Female ; Genotype ; Humans ; Introns/genetics* ; Pedigree ; Phenotype ; Rh-Hr Blood-Group System/genetics*