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PubMed2025

BRCA1 Exon 11 Mutations in Breast Cancer: A Study From Pakistan.

Breast cancer ranks among the top causes of cancer-related deaths in women around the globe, with genetic mutations in the BRCA1 gene being a frequent cause of breast or ovarian cancer. This study investigates hotspot mutations in exon 11 of the BRCA1 gene among Pakistani women diagnosed with breast cancer. Thirty clinically diagnosed breast cancer patients, all women, were enrolled in the current study, and high-quality DNA was extracted from peripheral blood samples. Two of the twenty-five successfully sequenced samples had a homozygous missense variant (c.2312T > C: p.Leu771Ser) detected by Sanger sequencing after PCR amplification. Upon investigation in the ClinVar database, the identified variant showed conflicting interpretations of pathogenicity. Demographic data highlighted an early disease onset, showing that 56% of patients were under 50 years of age. The need for genetic screening was further supported by the fact that 24% of the patients had a positive family history of cancer. Our study emphasizes the necessity of screening BRCA1 gene mutations to better understand the pathogenic potential of the identified variants in the Pakistani population.

Humans↗
PubMed2025

Novel genetic determinants contribute to hearing loss in a central European cohort with enlarged vestibular aqueduct.

BACKGROUND: The enlarged vestibular aqueduct (EVA) is the most commonly detected inner ear malformation. Biallelic pathogenic variants in the SLC26A4 gene, coding for the anion exchanger pendrin, are frequently involved in determining Pendred syndrome and nonsyndromic autosomal recessive hearing loss DFNB4 in EVA patients. In Caucasian cohorts, the genetic determinants of EVA remain unknown in approximately 50% of cases. We have recruited a cohort of 32 Austrian patients with hearing loss and EVA to define the prevalence and type of pathogenic sequence alterations in SLC26A4 and discover novel EVA-associated genes. METHODS: Sanger sequencing, single nucleotide polymorphism (SNP) assays, copy number variation (CNV) testing, and Exome Sequencing (ES) were employed for gene analysis. Cell-based functional and molecular assays were used to discriminate between gene variants with and without impact on protein function. RESULTS: SLC26A4 biallelic variants were detected in 5/32 patients (16%) and monoallelic variants in 5/32 patients (16%). The pathogenicity of the uncharacterized SLC26A4 protein variants was assigned or excluded based on their ion transport function and cellular abundance. The monoallelic or biallelic Caucasian EVA haplotype was detected in 7/32 (22%) patients, but its pathogenicity could not be confirmed. X-linked pathogenic variants in POU3F4 (2/32, 6%) and biallelic pathogenic variants in GJB2 (2/32, 6%) were also found. No CNV of SLC26A4 and STRC genes was detected. ES of eleven undiagnosed patients with bilateral EVA detected rare sequence variants in six EVA-unrelated genes (monoallelic variants in SCD5, REST, EDNRB, TJP2, TMC1, and two variants in CDH23) in five patients (5/11, 45%). Cell-based assays showed that the TJP2 variant leads to a mislocalized protein product forming dimers with the wild-type, supporting autosomal dominant pathogenicity. The genetic causes of hearing loss and EVA remained unidentified in (14/32) 44% of patients. CONCLUSIONS: The present investigation confirms the role of SLC26A4 in determining hearing loss with EVA, identifies novel genes in this pathophysiological context, highlights the importance of functional testing to exclude or assign pathogenicity of a given gene variant, proposes a possible diagnostic workflow, suggests a novel pathomechanism of disease for TJP2, and highlights voids of knowledge that deserve further investigation.

Humans↗
PubMed1992

Dideoxy fingerprinting (ddE): a rapid and efficient screen for the presence of mutations.

We describe dideoxy fingerprinting (ddF), a hybrid between dideoxy sequencing and SSCP that can detect the presence of single base and other sequence changes in PCR-amplified segments. As implemented herein, ddF involves a Sanger sequencing reaction with one dideoxynucleotide followed by nondenaturing gel electrophoresis. When ddF was used to examine segments of the human factor IX gene, 84 of 84 different mutations were detected with a very low rate of false positive signals. The approximate locations of the sequence changes could be determined from the ddF pattern and samples with different sequence changes had different fingerprints. In addition, large segments could be amplified and rapidly screened by ddF in multiple smaller subsegments. The patterns observed with ddF are instructive in that they suggest an inherent limitation in the detection of certain mutations by SSCP.

DNA Fingerprinting↗
PubMed2025

Clinical and Genetic Findings in Patients With Palmoplantar Keratoderma.

IMPORTANCE: Palmoplantar keratoderma poses diagnostic challenges due to its clinical and genetic heterogeneity, and knowledge on the value of systematic genetic testing on clinically well-described patient cohorts is sparse. OBJECTIVE: To improve knowledge of the clinical and genetic spectrum of patients with palmoplantar keratoderma. DESIGN, SETTING, AND PARTICIPANTS: This cohort study prospectively recruited patients and affected family members with palmoplantar keratoderma between September 1, 2016, and December 31, 2022. Patients were recruited from private practitioners in dermatology and dermatology departments in Denmark. Study participants were patients 18 years or older either newly diagnosed with palmoplantar keratoderma or being followed up for the disease at referral centers. MAIN OUTCOMES AND MEASURES: Phenotypes and clinical subtypes were classified. Genetic testing was performed by whole-exome or genome sequencing using an in silico panel containing genes related to palmoplantar keratoderma, or by Sanger sequencing for specific variants. Descriptive analysis, such as proportions and frequency, were used to describe clinical characteristics, distribution of disease-causing variants, and genotype-phenotype associations. RESULTS: This study included 142 study participants from 76 families (90 [63%] female; median [range] age, 52 [18-92] years). Clinical subtypes included 42 punctate (55%), 26 diffuse (34%), 5 focal (7%), and 3 striate (4%). A genetic diagnosis was found in 63 of 76 families (83%), including 27 disease-causing variants within 13 different genes: AAGAB (n = 39), DSG1 (n = 8), KRT1 (n = 3), DSP (n = 2), KRT9 (n = 2), AQP5 (n = 2), KRT16 (n = 1), SERPINA12 (n = 1), ABCA12 (n = 1), COL7A1 (n = 1), CARD14 (n = 1), DST (n = 1), and LORICRIN (n = 1). All participants with AAGAB variants presented with punctate palmoplantar keratoderma, showing a clear genotype-phenotype correlation. The other subtypes (diffuse, focal, and striate) proved more challenging to clinically subclassify, and disease-causing variants were identified in 12 genes, contributing to more complex genotype-phenotype patterns. Patients with palmoplantar keratoderma due to DSP variants were found, which is important to identify because of an associated risk of cardiomyopathy. CONCLUSION AND RELEVANCE: This study provides novel insights into the clinical and genetic spectrum of patients with palmoplantar keratoderma. It demonstrates the value of genetic testing for accurate diagnoses and to distinguish between different subtypes. The established and well-described cohort lays the foundation for future research in palmoplantar keratoderma.

Humans↗
PubMed1996

DNA sequencing by mass spectrometry.

Mass spectrometry has the potential to replace gel electrophoresis for fast DNA sequencing. In this tutorial paper, it is discussed how far mass spectrometry of DNA has come since the advent of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) and how much remains to be done before mass spectrometry will be a useful tool for DNA sequencing. A brief description of MALDI and ESI mass spectrometric analysis of DNA is presented along with the different strategies for DNA sequencing using mass spectrometry. These include mass spectrometric analysis to replace gel separation in Sanger sequencing, enzymatic ladder sequencing and sequencing by gas-phase fragmentation. The future role of mass spectrometry in DNA sequencing in the Human Genome Project and beyond is also discussed.

Animals↗
PubMed2026

Novel TCOF1 Frameshift Variant and Phenotypic Heterogeneity in a Chinese Family With Treacher Collins Syndrome.

BACKGROUND: Treacher Collins syndrome (TCS) is a congenital craniofacial disorder characterized by malar and mandibular hypoplasia, downward-slanting palpebral fissures, and conductive hearing loss. Pathogenic variants in TCOF1 account for most cases, with POLR1D, POLR1C, and POLR1B also implicated. METHODS: Whole-exome sequencing was performed in a two-generation Chinese family with TCS, followed by Sanger sequencing validation. Clinical features were systematically evaluated, and bioinformatic analyses combined with structural modeling were employed to assess the potential pathogenicity of the identified variant. RESULTS: In this study, a novel heterozygous frameshift variant in TCOF1 (NM_001371623.1:c.1601_1602delCC, p.Pro534Leufs*15) was identified in the proband and his affected father. The proband presented classic TCS features including craniofacial skeletal hypoplasia, downward-slanting palpebral fissures, and conductive hearing loss. He also carried a right-sided preauricular fistula, a nonclassical feature of TCS. The same variant was detected in his affected father with a substantially milder phenotype, indicating marked intrafamilial phenotypic variability. Bioinformatic analysis and structural modeling predicted that this variant produces a severely truncated Treacle protein lacking key functional domains, which is predicted to disrupt nucleolar localization and ribosome biogenesis. CONCLUSION: Our findings expand the variant spectrum of TCOF1, highlight phenotypic heterogeneity in TCS, and reinforce the critical role of molecular diagnosis in distinguishing TCS from phenotypically overlapping craniofacial syndromes.

Humans↗
PubMed2026

A novel FLNA p.Pro2469Ser variant is associated with impaired T and NK cell function and immune dysregulation.

FLNA encodes filamin A, a ubiquitously expressed actin-binding cytoskeletal protein that cross-links actin filaments and links them to membrane-associated signaling complexes. Although FLNA has been implicated in T-cell signaling and regulatory T-cell development in murine models, its role in human immune-cell function remains incompletely understood. Here, we investigated the immunological phenotype associated with a novel hemizygous FLNA variant identified in a pediatric patient presenting with recurrent infections and inflammatory manifestations. Whole-exome sequencing revealed a hemizygous c.7405C>T (p.Pro2469Ser) variant in FLNA, which was confirmed by Sanger sequencing. Its potential impact on immune-cell function and cytoskeletal organization was evaluated using confocal microscopy, flow cytometry, and molecular assays. Patient-derived T cells showed impaired activation and proliferation following CD3/CD28 and IL-2 stimulation, accompanied by reduced CD25 and CD69 upregulation. CD4+ T cells also exhibited reduced IFN-γ, TNF-α, and IL-2 production after stimulation. Despite elevated basal phospho-STAT5 levels, IL-2-induced STAT5 phosphorylation and TCR-associated signaling responses, including pZAP70, pLCK, and p38 MAPK activation, were attenuated. Confocal imaging together with image-based quantification demonstrated altered cortical cytoskeletal organization in patient T cells despite preserved FLNA expression. In parallel, NK cells showed impaired activation responses and reduced cytotoxic activity under the assay conditions used. Increased apoptosis was observed in CD4⁺, CD8⁺, and NK-cell populations. Inflammatory cytokines were elevated in plasma and colonic tissue, whereas colonic ZO-1 and FLNA expression were reduced. Collectively, these findings indicate that the FLNA p.Pro2469Ser variant is associated with altered immune-cell signaling, disturbed cortical cytoskeletal organization, and immune dysregulation. This study expands the phenotypic spectrum linked to FLNA variants and supports a role for filamin A in human immune-cell regulation.

Humans↗
PubMed2025

A Subset of Serous Tubal Intraepithelial Carcinoma (STIC)-Like Lesions and Concurrent High-Grade Endometrial Carcinoma Are Genomically Related Entities.

In patients with high-grade endometrial carcinoma (HG-EC), concurrent isolated serous tubal intraepithelial carcinoma (STIC) or STIC-like lesions (STIC-LLs) in the fallopian tube(s) may be found. We sought to determine whether concurrently diagnosed HG-ECs and STIC-LLs are genetically related. Six HG-ECs, including serous carcinomas (n = 4) and carcinosarcomas with serous epithelial component (n = 2), with cooccurring STIC-LLs were identified and subjected to microdissection, DNA extraction, and panel sequencing targeting 468 cancer-related genes or, if DNA quantities were limited, to Sanger sequencing. WT1 and p53 protein expression was assessed by immunohistochemistry. We found that 3 HG-ECs and concurrent STIC-LLs shared pathogenic mutations, such as TP53 hotspot, NF2, FBXW7, and PIK3CA mutations. Immunohistochemical analysis revealed that the HG-EC of case 5 lacked WT1 expression and had aberrant p53 expression, although the matched STIC-LL displayed diffuse WT1 expression. Of the remaining 3 cases that did not show evidence of genetic relatedness based on the targeted sequencing panel, 1 STIC-LL harbored a clonal TP53 missense mutation, whereas the matched HG-EC had a distinct clonal TP53 hotspot mutation, a clonal FBXW7 hotspot mutation, and ERBB2 amplification. At the protein level, the p53 expression patterns of the HG-ECs and STIC-LLs were concordant in these 3 cases. Here, we demonstrate that cooccurring HG-ECs and STIC-LLs are genetically related in a subset of cases.

Humans↗
PubMed2026

Biallelic pathogenic variants in FLNB are associated with paediatric steroid-resistant nephrotic syndrome via podocyte cytoskeletal dysfunction.

BACKGROUND: Steroid-resistant nephrotic syndrome (SRNS) is a severe paediatric kidney disease and a leading cause of end-stage kidney disease in children, with a high genetic contribution. While over 80 monogenic causes of SRNS have been identified, a significant proportion of affected patients still lack a clear genetic diagnosis, indicating that additional causative genes remain to be discovered. METHODS: Through whole-exome sequencing of a paediatric SRNS cohort, we identified three probands carrying biallelic FLNB pathogenic variants. Sanger sequencing was performed for familial cosegregation verification and ACMG classification. Expression of Filamin B, Nephrin and Synaptopodin in renal tissues was assessed by immunohistochemistry/immunofluorescence. Wild-type and patient-derived variant FLNB plasmids were constructed and transfected into HEK293T cells and immortalised human podocytes (HPCs). The effects of these variants on protein expression, localisation and cytoskeletal organisation were assessed by western blotting and immunofluorescence. FLNB expression in HPCs was silenced using shRNA to evaluate the impact on podocyte marker proteins, cytoskeletal integrity and migratory capacity. A zebrafish flnb knockdown model was employed to validate its effects on renal development. RESULTS: All three probands presented with isolated SRNS without skeletal developmental abnormalities, and renal tissues showed significantly reduced Filamin B protein expression. In vitro, p.L117P and p.M1803L variants led to markedly reduced protein expression, while p.R470L and p.K2586R induced perinuclear aggregation of Filamin B accompanied by F-actin rearrangement. FLNB silencing led to downregulation of Nephrin and Synaptopodin, cytoskeletal disorganisation and impaired cell migration. Zebrafish flnb knockdown exhibited pericardial oedema, defective nephron development and abnormal podocyte foot processes. CONCLUSION: We report for the first time that biallelic FLNB pathogenic variants are associated with paediatric SRNS by disrupting Filamin B expression, cytoskeletal integrity and podocyte function, providing evidence that FLNB is a novel monogenic cause of SRNS.

Humans↗
PubMed2025

Whole-exome sequencing uncovers the genetic basis of hereditary concomitant exotropia in ten Chinese pedigrees.

PURPOSE: To explore possible pathogenic genes for concomitant exotropia using whole-exome sequencing. METHODS: In this study, 47 individuals from 10 concomitant exotropia (including intermittent exotropia and constant exotropia) pedigrees were enrolled. Whole-exome sequencing was used to screen mutational profiles in 25 affected individuals and 10 unaffected individuals. Sanger sequencing and in silico analysis were performed for all participants. Two target genes were used to capture the sequences of 220 sporadic samples. RESULTS: All 10 concomitant exotropia pedigrees presented autosomal dominant inheritance with childhood onset (3.35 ± 1.51 years old). Eleven different missense variants were identified among seven potential pathogenic genes (COL4A2, SYNE1, LOXHD1, AUTS2, GTDC2, HERC2 and CDH3) that cosegregated with pedigree members. All variants were predicted to be deleterious and had low frequencies in the general population. Distinct variants of COL4A2 were present in three pedigrees, and distinct variants of SYNE1 were present in two pedigrees. Fifteen variants in AUTS2 and four variants in GTDC2 were identified in 220 patients with sporadic concomitant exotropia using a target-capture sequencing approach. CONCLUSION: This is the first study to explore the genetic mechanism of concomitant exotropia and identify seven associated genes (COL4A2, SYNE1, LOXHD1, AUTS2, GTDC2, HERC2 and CDH3) that may be candidate genes causing concomitant exotropia. More samples and in-depth studies are needed to verify these findings.

Adult↗
PubMed2025

Comprehensive analysis of a novel LYST mutation in a Tunisian patient with Chediak-Higashi syndrome.

BACKGROUND: Chediak-Higashi Syndrome (CHS) is a rare autosomal recessive disorder characterized by oculocutaneous albinism, recurrent infections, bleeding tendencies, and progressive neurological impairment. The syndrome is caused by mutations in the LYST gene, which plays a crucial role in lysosomal trafficking. OBJECTIVE: This study aims to characterize the molecular basis of CHS in a Tunisian patient by identifying mutations in the LYST gene and analyzing their impact on the protein function, correlating these findings with the patient's clinical presentation. METHODS: A comprehensive clinical assessment was conducted on the patient, followed by biochemical, hematological, and microbiological analyses. Additionally, LYST protein levels were quantified in the patient and their parents using an ELISA assay. Genomic DNA was extracted from the patient's blood, and Whole Exome Sequencing (WES) was performed to identify mutations in the LYST gene. The findings were confirmed through Sanger sequencing, and bioinformatic tools were employed to predict the functional consequences of the detected mutations. RESULTS: The patient presented with classical symptoms of CHS, including silver hair, hypopigmented skin, recurrent infections, and neurological decline, with an unusually late onset at 18 years. ELISA results demonstrated significantly reduced LYST levels in the patient (1.8 ng/ml) compared to heterozygous parents (7.8 ng/ml and 8.1 ng/ml) and controls (9.2 ng/ml). Genetic analysis revealed a novel homozygous deletion, c.10269_10275del (p.Gly3424SerfsTer15), in the LYST gene, leading to a frameshift mutation and premature termination of the protein. Bioinformatic analysis demonstrated that this mutation leads to the deletion of five out of sven WD40 repeats in the protein's C-terminal region, which are critical for protein-protein interactions and lysosomal trafficking. CONCLUSION: The study identifies a novel LYST mutation in a Tunisian patient with CHS, expanding the spectrum of known genetic variants associated with the disease. The findings highlight the importance of genetic screening in populations with high consanguinity and underscore the need for targeted therapies to address the molecular defects in CHS.

Adolescent↗
PubMed2026

Identification of a Novel Splice-Site variant in TACR3 (c.888 + 1G > A) Associated with Asthenozoospermia and Hypogonadotropic Hypogonadism in an Iranian Family.

BACKGROUND: TACR3 encodes the receptor for neurokinin B, a key regulator of the hypothalamic-pituitary-gonadal axis. Disruption of this pathway can impair gonadotropin release and male reproductive function. Given the genetic heterogeneity of male infertility, this study aimed to identify novel variants in TACR3 that may underlie asthenozoospermia and related hormonal abnormalities. METHODS: Fifteen infertile men with confirmed asthenozoospermia were enrolled. Whole-exome sequencing (WES) was performed on genomic DNA from peripheral blood, and the candidate variant was validated by Sanger sequencing. Functional predictions were made using PolyPhen-2, SIFT, MutationTaster, and REVEL. TACR3 mRNA expression levels were assessed by real-time PCR in available samples. RESULTS: A novel splice-site variant, TACR3 (NM_001059.3:c.888 + 1G > A), was detected and found to segregate with infertility in one family, appearing homozygously in two infertile brothers and heterozygously in the proband with severe asthenozoospermia. The variant was absent in public and local genomic databases, suggesting its extremely rare frequency. Furthermore, RT-PCR showed a dramatic reduction or complete loss of TACR3 expression in affected individuals, confirming its deleterious effect on splicing and mRNA stability. CONCLUSION: We identified a previously unreported splice-site mutation in TACR3 (c.888 + 1G > A) that likely causes familial infertility by disrupting the neurokinin B/NK3R signaling pathway. While the heterozygous proband exhibited severe asthenozoospermia, the homozygous brothers displayed hormonal profiles typical of hypogonadotropic hypogonadism. These findings extend the mutational landscape of TACR3 and highlight its essential contribution to male reproductive endocrinology.

Humans↗
PubMed2004

Pyrosequencing for detection of lamivudine-resistant hepatitis B virus.

Chronic hepatitis B virus (HBV) infection can cause severe liver disease, including cirrhosis and hepatocellular carcinoma. Lamivudine is a relatively recent alternative to alpha interferon for the treatment of HBV infection, but unfortunately, resistance to lamivudine commonly develops during monotherapy. Lamivudine-resistant HBV mutants display specific mutations in the YMDD (tyrosine, methionine, aspartate, aspartate) motif of the viral polymerase (reverse transcriptase [rt]), which is the catalytic site of the enzyme, i.e., methionine 204 to isoleucine (rtM204I) or valine (rtM204V). The latter mutation is often accompanied by a compensatory leucine-to-methionine change at codon 180 (rtL180M). In the present study, a novel sequencing method, pyrosequencing, was applied to the detection of lamivudine resistance mutations and was compared with direct Sanger sequencing. The new pyrosequencing method had advantages in terms of throughput. Experiments with mixtures of wild-type and resistant viruses indicated that pyrosequencing can detect minor sequence variants in heterogeneous virus populations. The new pyrosequencing method was evaluated with a small number of patient samples, and the results showed that the method could be a useful tool for the detection of lamivudine resistance in the clinical setting.

Base Sequence↗
PubMed2026

[A case of bilateral open-lip schizencephaly with West syndrome due to variant of PAFAH1B1 gene and literature review].

OBJECTIVE: To report the clinical manifestations, genetic features, diagnosis, treatment, and prognosis of a child with bilateral open-lip schizencephaly complicated by West syndrome due to a variant of PAFAH1B1 gene, and review the relevant literature. METHODS: Clinical data of a 4-month-old boy were retrospectively analyzed, and 35 previously reported cases were systematically reviewed. This study was approved by the Medical Ethics Committee of Gansu Provincial People's Hospital (Ethics No.: 2025-871). RESULTS: The 4-month-old boy presented with clustered flexor spasms, hypsarrhythmia on electroencephalography, and developmental regression. Brain magnetic resonance imaging revealed bilateral pachygyria, schizencephaly, and dysgenesis of the corpus callosum. Trio whole-exome sequencing identified a de novo heterozygous NM_000430.4: c.703_704delAG (p.Glu235Metfs*20) frameshift variant in the PAFAH1B1 gene. Sanger sequencing confirmed that neither parent carried this variant. Based on the guidelines from American College of Medical Genetics and Genomics (ACMG), the variant has met the criteria for PVS1+PS2_Moderate+PM2_Supporting, and was classified as pathogenic. After treatment with adrenocorticotropic hormone combined with vigabatrin and other antiseizure medications, the epileptic spasms were controlled and the electroencephalographic abnormalities had improved. However, global developmental delay persisted at the 12-month follow-up. Analysis of the present case and 35 previously reported cases showed that PAFAH1B1-related phenotypes were highly consistent, mainly including infantile spasms (28/36), developmental delay/intellectual disability (29/36), and abnormal brain MRI findings (30/36), predominantly cortical malformations. The reported variant types included deletions, frameshift variants, nonsense variants, missense variants, and splice-site variants. CONCLUSION: PAFAH1B1 gene variants are an important cause for cortical malformations, including schizencephaly, and may lead to secondary West syndrome. This study has systematically summarized the genotypic and phenotypic features of bilateral open-lip schizencephaly complicated by West syndrome associated with a frameshift variant of the PAFAH1B1 gene. For infants with epileptic spasms or early-onset epilepsy accompanied by structural brain abnormalities, early genetic evaluation should be performed, and antiseizure treatment should be integrated with neurodevelopmental rehabilitation to facilitate long-term management.

Humans↗
PubMed2026

Novel biallelic FSIP2 variants cause male infertility with multiple morphological abnormalities of sperm flagella in humans.

Biallelic variants in fibrous sheath-interacting protein 2 ( FSIP2 ) gene are a known cause of multiple morphological abnormalities of the sperm flagella (MMAF). This study aimed to identify novel FSIP2 variants and evaluate their impact on sperm ultrastructure and intracytoplasmic sperm injection (ICSI) outcomes. Whole-exome sequencing (WES) was employed to screen a cohort of 92 MMAF patients, with candidate variants validated via Sanger sequencing and third-generation sequencing. We identified one homozygous variant in a proband from a consanguineous family and two pairs of compound heterozygous variants in two unrelated, non-consanguineous families. Routine semen analysis demonstrated markedly reduced motility across all probands. Detailed morphological and ultrastructural assessments using Papanicolaou staining, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) demonstrated that approximately 80.0% of spermatozoa exhibited pathological elongation of the mitochondrial sheath in the midpiece. Furthermore, 50.0%-70.0% of spermatozoa displayed fibrous sheath dysplasia or loss in the principal piece. Immunofluorescence assays and Western blotting confirmed that FSIP2 protein localization was disrupted, and the expression of key axonemal assembly factors was dysregulated. Notably, successful pregnancies were achieved via ICSI in the partners of two probands. This study expands the mutational spectrum of FSIP2 in both consanguineous and non-consanguineous populations. Ultrastructural abnormalities, such as mitochondrial sheath elongation and fibrous sheath disassembly, highlight FSIP2 's critical role in flagellar assembly. Clinical results further support ICSI as an effective therapeutic intervention for affected individuals.

Humans↗
PubMed1986

Nucleotide sequence and deduced amino acid sequence of Escherichia coli pyruvate oxidase, a lipid-activated flavoprotein.

The entire nucleotide sequence of the poxB (pyruvate oxidase) gene of Escherichia coli K-12 has been determined by the dideoxynucleotide (Sanger) sequencing of fragments of the gene cloned into a phage M13 vector. The gene is 1716 nucleotides in length and has an open reading frame which encodes a protein of Mr 62,018. This open reading frame was shown to encode pyruvate oxidase by alignment of the amino acid sequences deduced for the amino and carboxy termini and several internal segments of the mature protein with sequences obtained by amino acid sequence analysis. The deduced amino acid sequence of the oxidase was not unusually rich in hydrophobic sequences despite the peripheral membrane location and lipid binding properties of the protein. The codon usage of the oxidase gene was typical of a moderately expressed protein. The deduced amino acid sequence shares homology with the large subunits of the acetohydroxy acid synthase isozymes I, II, and III, encoded by the ilvB, ilvG, and ilvI genes of E. coli.

Acetolactate Synthase↗
PubMed2026

Analysis of CYLD gene variants in 41 patients with multiple familial trichoepithelioma.

OBJECTIVE: To investigate the variants of the CYLD gene in Chinese patients with multiple familial trichoepithelioma (MFT), aiming to provide a scientific basis for genetic counseling and prenatal diagnosis, thereby creating favorable conditions for intervention treatment and improving the prognosis of patients. PATIENTS AND METHODS: Whole-exome sequencing (WES) was performed in patients from eleven families to identify candidate variants, which were subsequently confirmed by Sanger sequencing. The minigene technique was used to perform functional analyses of the variants c.2342-8C>G and c.1685-9T>G. Whole-genome sequencing (WGS) was applied in patients with negative WES results. RESULTS: All 41 patients presented with multiple papules or nodules on the nose. We identified six novel pathogenic variants and three recurrent pathogenic variants. Conversely, no gene variants were detected in four patients. The c.1685-9T>G variant caused aberrant mRNA splicing, resulting in the insertion of an 8-base intronic sequence into the mRNA and subsequent premature termination, while the variant c.2342-8C>G led to premature mRNA splicing seven bases upstream of the canonical splice site. CONCLUSIONS: This study identified six novel and three recurrent pathogenic variants in the CYLD gene among 41 patients with MFT. Comprising the largest sample size report in this field to date, this work considerably expands the mutational spectrum of the CYLD gene (currently comprising 144 variants) and carries important implications for genetic counseling.

Humans↗
PubMed2006

Nanopore sequencing technology: research trends and applications.

Nanopore sequencing is one of the most promising technologies being developed as a cheap and fast alternative to the conventional Sanger sequencing method. Protein or synthetic nanopores have been used to detect DNA or RNA molecules. Although none of the technologies to date has shown single-base resolution for de novo DNA sequencing, there have been several reports of alpha-hemolysin protein nanopores being used for basic DNA analyses, and various synthetic nanopores have been fabricated. This review will examine current nanopore sequencing technologies, including recent developments of new applications.

Biosensing Techniques↗