Project description:Chronic granulomatous disease (CGD) is caused by gene mutations that affect the phagocyte NADPH oxidase. This results in recurrent infections by catalase-positive bacteria or fungi. Here, we report a case of X-linked CGD presenting a mixed infection with Burkholderia cepacia and Aspergillus. A novel mutation was found by bioinformatics analyses of his genealogy (c.1234delG), which perhaps changed the structure and function of the related proteins.
Project description:Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive neuromuscular diseases resulting from dystrophin (DMD) gene mutations. It has been known that the carrier of DMD mutations may also have symptoms of the disease. While de novo mutation is quite common in BMD/DMD patients, it is rarely reported in the female carriers.Two sporadic Chinese patients with progressive muscular dystrophy and their familial members were recruited. The targeted next-generation sequencing (NGS) and the multiplex ligation-dependent probe analysis (MLPA) were performed in the proband. Blood tests, electrocardiography, echocardiography, and electromyography were also evaluated.Two novel mutations of DMD gene were identified, c.7318C>T (p.Q2440*) in the male proband and c.4983dupA (p.A1662Sfs*24) in the female carrier. The MLPA analysis did not detect any large rearrangements. The haplotype analysis indicated that the two mutations were derived from de novo mutagenesis.We identified two novel de novo mutations of DMD gene in two Chinese pedigrees, one of which caused a female patient with muscular dystrophy. The mutational analysis is important for DMD patients and carriers in the absence of a family history. The NGS can help detect the mutations in MLPA-negative patients.
Project description:BACKGROUND: Börjeson-Forssman-Lehmann syndrome (BFLS; MIM 301900) is an infrequently described X linked disorder caused by mutations in PHF6, a novel zinc finger gene of unknown function. OBJECTIVE: To present the results of mutation screening in individuals referred for PHF6 testing and discuss the value of prior X-inactivation testing in the mothers of these individuals. RESULTS: 25 unrelated individuals were screened (24 male, one female). Five PHF6 mutations were detected, two of which (c.940A-->G and c.27_28insA) were novel. One of these new mutations, c.27_28insA, was identified in a female BFLS patient. This was shown to be a de novo mutation arising on the paternal chromosome. This is the first report of a clinically diagnosed BFLS female with a confirmed PHF6 mutation. In addition, the X-inactivation status of the mothers of 19 males with suggested clinical diagnosis of BFLS was determined. Skewed (> or =70%) X-inactivation was present in five mothers, three of whom had sons in whom a PHF6 mutation was detected. The mutation positive female also showed skewing. CONCLUSIONS: The results indicate that the success of PHF6 screening in males suspected of having BFLS is markedly increased if there is a positive family history and/or skewed X-inactivation is found in the mother.
Project description:BackgroundChronic Granulomatous Disease (CGD) is a primary immunodeficiency that causes susceptibility to recurrent fungal and bacterial infections. The CYBB gene encodes gp91phox component of the Phagocytic Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and specifically, X-linked CGD is caused by mutations in the CYBB gene, located on the X chromosome. The aim of the study was to characterize functional and genetic mutations in X-linked CGD.MethodsFunctional analysis was conducted on the whole blood of seventeen male individuals who were suspected to have X-linked chronic granulomatous disease (CGD). Flow cytometry was employed to assess the capacity of NADPH oxidase, measuring both H2O2 production and gp91phox protein expression in neutrophils. Additionally, DNA Sanger sequencing was performed for genetic analysis. The pathogenicity of novel mutations was assessed by pathogenicity prediction tools.ResultAmong the seventeen patients evaluated, five patients (P1, P2, P3, P4, and P5) displayed impaired H2O2 production by their neutrophils upon stimulation with Phorbol myristate acetate (PMA), accompanied by abnormal gp91phox expression. DNA sequencing of the CYBB gene identified specific mutations in each patient. In P1 and P2 (previously reported cases), a hemizygous missense mutation, c.925G > A/p.E309K was identified. In P3 and P4 (novel cases), hemizygous nonsense mutations, c.216T > A/p.C72X were found. Lastly, in P5 (also a novel case), a hemizygous missense mutation, c.732T > G/p.C244W was detected. These mutations reside in exons 9,3 and 7 of the CYBB gene, respectively.ConclusionsThe current study contributes to the understanding of the clinical and genetic spectrum associated with X-linked chronic granulomatous disease (CGD). It highlights the significance of early diagnosis in CGD and emphasizes the importance of lifelong prophylaxis to prevent severe infections.
Project description:Objective:To determine the disease relevance of a novel de novo dominant variant in the SLC25A4 gene, encoding the muscle mitochondrial adenosine diphosphate (ADP)/adenosine triphosphate (ATP) carrier, identified in a child presenting with a previously unreported phenotype of mild childhood-onset myopathy. Methods:Immunohistochemical and western blot analysis of the patient's muscle tissue were used to assay for the evidence of mitochondrial myopathy and for complex I-V protein levels. To determine the effect of a putative pathogenic p.Lys33Gln variant on ADP/ATP transport, the mutant protein was expressed in Lactococcus lactis and its transport activity was assessed with fused membrane vesicles. Results:Our data demonstrate that the heterozygous c.97A>T (p.Lys33Gln) SLC25A4 variant is associated with classic muscle biopsy findings of mitochondrial myopathy (cytochrome c oxidase [COX]-deficient and ragged blue fibers), significantly impaired ADP/ATP transport in Lactococcus lactis and decreased complex I, III, and IV protein levels in patient's skeletal muscle. Nonetheless, the expression levels of the total ADP/ATP carrier (AAC) content in the muscle biopsy was largely unaffected. Conclusions:This report further expands the clinical phenotype of de novo dominant SLC25A4 mutations to a childhood-onset, mild skeletal myopathy, without evidence of previously reported clinical features associated with SLC25A4-associated disease, such as cardiomyopathy, encephalopathy or ophthalmoplegia. The most likely reason for the milder disease phenotype is that the overall AAC expression levels were not affected, meaning that expression of the wild-type allele and other isoforms may in part have compensated for the impaired mutant variant.
Project description:X-linked chronic granulomatous disease (X-CGD) is a primary immunodeficiency caused by mutations in the CYBB gene, resulting in the inability of phagocytic cells to eliminate infections. To design a lentiviral vector (LV) capable of recapitulating the endogenous regulation and expression of CYBB, a bioinformatics-guided approach was used to elucidate the cognate enhancer elements regulating the native CYBB gene. Using this approach, we analyzed a 600-kilobase topologically associated domain of the CYBB gene and identified endogenous enhancer elements to supplement the CYBB promoter to develop MyeloVec, a physiologically regulated LV for the treatment of X-CGD. When compared with an LV currently in clinical trials for X-CGD, MyeloVec showed improved expression, superior gene transfer to hematopoietic stem and progenitor cells (HSPCs), corrected an X-CGD mouse model leading to complete protection against Burkholderia cepacia infection, and restored healthy donor levels of antimicrobial oxidase activity in neutrophils derived from HSPCs from patients with X-CGD. Our findings validate the bioinformatics-guided design approach and have yielded a novel LV with clinical promise for the treatment of X-CGD.
Project description:Jacobsen syndrome (OMIM #147791) is a rare contiguous gene disorder caused by deletions in distal 11q. The clinical phenotype is variable and can include dysmorphic features, varying degrees of intellectual disability, behavioral problems including autism and attention deficit hyperactivity disorder, congenital heart defects, structural kidney defects, genitourinary problems, immunodeficiency, and a bleeding disorder due to impaired platelet production and function. Previous studies combining both human and animal systems have implicated several disease-causing genes in distal 11q that contribute to the Jacobsen syndrome phenotype. One gene, ETS1, has been implicated in causing congenital heart defects, structural kidney defects, and immunodeficiency. We performed a comprehensive phenotypic analysis on a patient with congenital heart disease previously found to have a de novo frameshift mutation in ETS1, resulting in the loss of the DNA-binding domain of the protein. Our results suggest that loss of Ets1 causes a "partial Jacobsen syndrome phenotype" including congenital heart disease, facial dysmorphism, intellectual disability, and attention deficit hyperactivity disorder.
Project description:We describe a female with Rett syndrome carrying a rare de novo mosaic nonsense mutation on MECP2 gene, with random X-chromosome inactivation. Rett syndrome severity in females depends on mosaicism level and tissue specificity, X-chromosome inactivation, epigenetics and environment. Rett syndrome should be considered in both males and females.
Project description:Trisomy 9p syndrome is the fourth most frequent chromosome aberration seen in infants. Duplication of the critical region 9p22p24 leads to mental retardation, psychomotor delay, and craniofacial and digital anomalies. We report a 2-year-old Ecuadorian girl with Trisomy 9p syndrome. Although her phenotype shares characteristics of Noonan syndrome, Giemsa trypsin banding technique shows there is an extra chromosomal segment on chromosome 14, and array analysis shows that it belongs to a duplication of 38 Mb of 9p13.1p24.3. Fluorescence in situ hybridization analysis detected three signals from 9p chromosome. The duplication is de novo, being another unique case of the few reported in the literature.
Project description:IntroductionX-linked recessive chronic granulomatous disease (XR-CGD) is a severe primary immunodeficiency principally caused by a CYBB (OMIM: 300481) gene variant. Recurrent fatal bacterial or fungal infections are the main clinical manifestations of XR-CGD.Patient concernsIn the current case, in vitro fertilization (IVF) associated with preimplantation genetic testing for monogenic disorder (PGT-M) was applied for a Chinese couple who had given birth to a boy with XR-CGD.DiagnosisNext-generation sequencing-based SNP haplotyping and Sanger-sequencing were used to detect the CYBB gene variant (c.804 + 2T>C, splicing) in this family.InterventionsThe patient was treated with IVF and PGT-M successively.OutcomesIn this IVF cycle, 7 embryos were obtained, and 2 of them were euploid and lacked the CYBB gene variant (c.804 + 2T>C). The PGT results were verified by prenatal diagnosis after successful pregnancy, and a healthy girl was eventually born.ConclusionPGT-M is an effective method for helping families with these fatal and rare inherited diseases to have healthy offspring. It can availably block the transmission of disease-causing loci to descendant.