Humans ; Kallmann Syndrome/genetics* ; Mutation, Missense ; Mutation

OBJECTIVE: To detect pathogenic variants in a pedigree affected with propionic acidemia (PA). METHODS: The proband was subjected to high-throughput next-generation sequencing. Suspected variants were validated by Sanger sequencing of his family members. mRNA was extracted from peripheral blood lymphocytes from the proband's father in order to verify the impact of the splicing variant by RT-PCR combined with Sanger sequencing. The pathogenicity of the missense variant was predicted by using PolyPhen-2, Mutation Taster, SIFT, COBALT and HOPE software. RESULTS: The proband was found to harbor compound heterozygous variants of the PCCB gene, namely c.184-2A>G and c.733G>A (p.G245S), which were respectively inherited from his father and mother. RT-PCR combined with Sanger sequencing confirmed skipping of exon 2 during transcription. Bioinformatic analysis indicated the c.733G>A (p.G245S) variant to be damaging. CONCLUSION The two variants of the PCCB gene probably underlay the disease in this patient. Above findings have enriched the spectrum of PCCB gene variants.
Exons ; Humans ; Mutation ; Mutation, Missense ; Pedigree ; Propionic Acidemia/genetics*

OBJECTIVE: To analyze the different subtypes caused by c.721C>T substitution in the exon 7 of the ABO gene, and to investigate the related molecular mechanism of different antigens expression. METHODS: ABO subtypes in 7 samples were identified by standard serological methods. The exons 6, 7, and adjacent intron of ABO gene were amplified by Polymerase Chain Reaction (PCR), and the PCR products were analyzed by direct DNA sequencing and cloning sequencing. RESULTS: ABO subtypes phenotypes were A CONCLUSION c.721C>T substitution in the ABO gene causes p.Arg241Trp exchange resulting in the decreasing of GTA or GTB activities and weaker antigen expression. O.01.07 is a null allele which cannot form a functional catalytic enzyme has no effect on A
ABO Blood-Group System/genetics* ; Alleles ; Exons ; Genotype ; Mutation, Missense

OBJECTIVE: To explore the characteristics of PAH gene variants among 113 phenylketonuria patients from Henan Province. METHODS: The 13 exons of the PAH gene were subjected to PCR amplification and direct sequencing. Large fragment deletion and duplication of the PAH gene were detected with a multiple ligation-dependent probe amplification (MLPA) assay. RESULTS: In total 195 point variants and 3 large fragment deletions were detected among the 226 alleles, with the detection rates being 86.28% and 1.33%, respectively. Variants of p.Arg243Gln (18.14%), p.Arg111X (6.19%), p.Arg53His (5.31%), EX6-96A>G (5.31%), p.Tyr356X (4.87%) and p.Val399Val (4.42%) were relatively common. Most of the variants were located in exons 7, 11, 3 and 6. Missense variations were most common. Four novel variations were detected, which included c.1016C>A (p.Ser339Tyr), c.1000T>C (p.Cys334Arg), c.1110G>T (p.Glu370Asp), and IVS6+1G>T. CONCLUSION The PAH gene variations in Henan Province have featured extensive allelic heterogeneity and variety.
China ; Exons ; Humans ; Mutation, Missense ; Phenylalanine Hydroxylase ; genetics ; Phenylketonurias ; genetics ; Point Mutation ; Sequence Deletion

OBJECTIVE: To explore the clinical characteristics and genetic basis of a child with Kartagener syndrome (KTS). METHODS: Trio-whole exome sequencing was carried out for the child and his parents, and candidate variants were verified by Sanger sequencing. Changes in protein structure due to missense variants were simulated and analyzed, and the Human Splicing Finder 3.0 (HSF 3.0) online platform was used to predict the effect of the variant of the non-coding region. RESULTS: The child had featured bronchiectasis, sinusitis and visceral inversion. Genetic testing revealed that he has harbored compound heterozygous variants of the DNAH5 gene, namely c.5174T>C and c.7610-3T>G. Sanger sequencing confirmed the existence of the variants. The variants were not found in the dbSNP, 1000 Genomes, ExAC, ClinVar and HGMD databases. Protein structural analysis suggested that the c.5174T>C (p.Leu1725Pro) variant may affect the stability of local structure and its biological activity. The results of HSF 3.0 analysis suggested that the c.7610-3T>G variant has probably destroyed a splicing receptor to affect the transcription process. CONCLUSION The compound heterozygous variants of the DNAH5 gene probably underlay the pathogenesis in the child. Above finding may facilitate the understanding of the clinical characteristics and genetic basis of KTS, and further expand the spectrum of DNAH5 gene variants.
Male ; Humans ; Child ; Mutation ; Kartagener Syndrome/genetics* ; Genetic Testing ; Mutation, Missense ; Exome Sequencing ; Axonemal Dyneins/genetics*

Objective: To investigate the molecular pathogenesis and clinical features of unrelated 12 patients with inherited coagulation protein C (PC) deficiency in Chinese population. Methods: The PC activity (PC:A) and PC antigen (PC:Ag) were detected by chromogenic substrate and enzyme linked immunosorbent assay, respectively. The nine exons and flanking sequences of the protein C (PROC) gene were amplified by polymerase chain reaction with direct sequencing, and the suspected mutations were validated by reverse sequencing (clone sequencing for deletion mutations) . Results: The PC:A of the 12 probands decreased significantly, ranging from 18% to 55%, and the PC:Ag of the 10 probands decreased significantly. Eleven mutations were found, out of which four mutations [c.383G>A (p.Gly128Asp) , c.997G>A (p.Ala291Thr) , c.1318C>T (p.Arg398Cys) , and c.532G>C (p.Leu278Pro) ] were discovered for the first time. Six mutations were in the serine protease domain, four mutations were located in epidermal growth factor (EGF) -like domains, and one mutation was located in activation peptide. There were two deletion mutations (p.Met364Trp fsX15 and p.Lys192del) , and the rest were missense mutations. Mutations p.Phe181Val and p.Arg189Trp were identified in three unrelated families. All mutations may be inherited, and consanguineous marriages were reported in two families. Among the probands, nine cases had venous thrombosis, two cases had poor pregnancy manifestations, and one case had purpura. Conclusion: Patients with PC deficiency caused by PROC gene defects are prone to venous thrombosis, especially when there are other thrombotic factors present at the same time.
Humans ; Mutation ; Mutation, Missense ; Pedigree ; Phenotype ; Protein C/genetics* ; Protein C Deficiency/genetics*

OBJECTIVE: To analyze the sequence of the F12 gene and molecular mechanism for 20 patients with coagulation factor Ⅻ (FⅫ) deficiency. METHODS: The patients were selected from the outpatient department of the Second Hospital of Shanxi Medical University from July 2020 to January 2022. The activity of coagulation factor Ⅷ (FⅧ:C), factor Ⅸ (FⅨ:C), factor Ⅺ (FⅪ:C) and factor Ⅻ (FⅫ:C) were determined by using a one-stage clotting assay. All exons and 5' and 3' UTR of the F12 gene were analyzed by Sanger sequencing to detect the potential variants. Bioinformatic software was used to predict the pathogenicity of the variants, conservation of amino acids, and protein models. RESULTS: The FⅫ:C of the 20 patients has ranged from 0.07% to 20.10%, which was far below the reference values, whilst the other coagulation indexes were all normal. Sanger sequencing has identified genetic variants in 10 patients, including 4 with missense variants [c.820C>T (p.Arg274Cys), c.1561G>A (p.Glu521Lys), c.181T>C (p.Cys61Arg) and c.566.G>C (p.Cys189Ser)], 4 deletional variants c.303_304delCA(p.His101GlnfsX36), 1 insertional variant c.1093_1094insC (p.Lys365GlnfsX69) and 1 nonsense variant c.1763C>A (p.Ser588*). The remaining 10 patients only harbored the 46C/T variant. The heterozygous c.820C>T(p.Arg274Cys) missense variant in patient 1 and the homozygous c.1763C>A (p.Ser588*) nonsense variant in patient 2 were not included in the ClinVar and the Human Gene Mutation Database. Bioinformatic analysis predicted that both variants were pathogenic, and the corresponding amino acids are highly conserved. The protein prediction models suggested that the c.820C>T (p.Arg274Cys) variant may affect the stability of the secondary structure of FⅫ protein by disrupting the original hydrogen bonding force and truncating the side chain, leading to changes in the vital domain. c.1763C>A (p.Ser588*) may produce a truncated C-terminus which may alter the spatial conformation of the protein domain and affect the serine protease cleavage site, resulting in extremely reduced FⅫ:C. CONCLUSION Among individuals with low low FⅫ:C detected by one-stage clotting assay, 50% have harbored variants of the F12 gene, among which the c.820C>T and c.1763C>A were novel variants underlying the reduced coagulating factor FⅫ.
Humans ; Factor XII/genetics* ; Pedigree ; Mutation ; Mutation, Missense ; Heterozygote ; Factor XII Deficiency/genetics*

Humans ; Mutation, Missense ; KCNQ1 Potassium Channel/genetics* ; Long QT Syndrome/genetics* ; Phenotype ; Mutation ; Pedigree

Humans ; Mutation, Missense ; KCNQ1 Potassium Channel/genetics* ; Long QT Syndrome/genetics* ; Phenotype ; Mutation ; Pedigree

OBJECTIVE: To explore the genetic basis for a sib pair featuring 17beta-hydroxysteroid dehydrogenase type 3 deficiency. METHODS: Genomic DNA was extracted from the proband, her sister, and their parents, and was subjected to sequencing analysis with a gene panel for sexual development. Suspected variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: Both the proband and her sister were found to harbor novel compound heterozygous missense variants of the HSD17B3 gene, namely c.839T>C (p.Leu280Pro) and c.239G>T (p.Arg80Leu), which were derived respectively from their mother and father. The variants were unreported previously and predicted to be deleterious by PolyPhen2, MutationTaster and other online software. Based on the American College of Medical Genetics and Genomics standards and guidelines, both c.839T>C(p.Leu280Pro) and c.239G>T (p.Arg80Leu) were predicted to be likely pathogenic (PM2+PP1+PP2+PP3+PP4, PM2+PM5+PP1+PP2+PP3+PP4). CONCLUSION The compound heterogeneous variants of the HSD17B3 gene probably underlay the disease in this sib pair. 17beta-hydroxysteroid dehydrogenase type 3 deficiency may lack specific clinical features and laboratory index, genetic testing can facilitate a definitive diagnosis.
17-Hydroxysteroid Dehydrogenases/genetics* ; Female ; Genetic Testing ; Genomics ; Humans ; Mutation ; Mutation, Missense