Gene Defects Research Articles

Lack of evidence that progesterone in ovulatory cycles causes breast cancer

A recent Perspective article asserted that progesterone secretion during ovulatory cycles is the cause of breast cancer. However, we challenge most of the evidence developed in this publication. First, there is a lack of evidence that progesterone is mutagenic for breast cells. Cause of a cancer should mean initiation by mutation, as opposed to promotion. Second, subclinical ovulatory disturbances occur rather frequently in normal-length menstrual cycles. Third, the authors attribute a potential carcinogenic effect to progesterone secreted during menstrual cycles but not to progesterone during pregnancy. They did not discuss breast cancer evidence from progesterone/progestin therapeutics. They argue that in genetic primary amenorrhea, a hypothetic lower risk of breast cancer could be due to the lack of progesterone, despite the progesterone/progestin in hormone replacements these women receive. Fourth, they advocate a regulatory effect of progesterone on several genes potentially involved in cancer genesis. In particular, they attribute a lower risk of breast cancer in women with Mayer–Rokitansky–Küster–Hauser syndrome to a defect in the progesterone-stimulated Wnt4 gene. However, this defect is only present in a small subset. Thus, the postulated progesterone breast cancer risk is unconvincing, which we discuss point by point in this commentary.

Bone fragility and osteoporosis in children and young adults.

Osteoporosis is a metabolic bone disorder which increases fragility fracture risk. Elderly individuals, especially postmenopausal women, are particularly susceptible to osteoporosis. Although rare, osteoporosis in children and young adults is becoming increasingly evident, highlighting the need for timely diagnosis, management and follow-up. Early-onset osteoporosis is defined as the presence of a low BMD (Z-score of ≤ -2.0 in individuals aged < 20years; T-score of ≤ -2.5 in those aged between 20 to 50years) accompanied by a clinically significant fracture history, or the presence of low-energy vertebral compression fractures even in the absence of osteoporosis. Affected children and young adults should undergo a thorough diagnostic workup, including collection of clinical history, radiography, biochemical investigation and possibly bone biopsy. Once secondary factors and comorbidities are excluded, genetic testing should be considered to determine the possibility of an underlying monogenic cause. Defects in genes related to type I collagen biosynthesis are the commonest contributors of primary osteoporosis, followed by loss-of-function variants in genes encoding key regulatory proteins of canonical WNT signalling (specifically LRP5 and WNT1), the actin-binding plastin-3 protein (encoded by PLS3) resulting in X-linked osteoporosis, and the more recent sphingomyelin synthase 2 (encoded by SGMS2) which is critical for signal transduction affecting sphingomyelin metabolism. Despite these discoveries, genetic causes and underlying mechanisms in early-onset osteoporosis remain largely unknown, and if no causal gene is identified, early-onset osteoporosis is deemed idiopathic. This calls for further research to unravel the molecular mechanisms driving early-onset osteoporosis that consequently will aid in patient management and individualised targeted therapy.

A biallelic loss-of-function variant in TMEM147 causes profound intellectual disability and spasticity.

Intellectual disability (ID), occurring in syndromic or non-syndromic forms, is the most common neurodevelopmental disorder. Although many cases are caused by single gene defects, ID is highly genetically heterogeneous. Biallelic variants in the transmembrane protein TMEM147 have recently been linked to intellectual disability with dysmorphic facial features. TMEM147 is believed to localize to the endoplasmic reticulum membrane and nuclear envelope and also involved in biogenesis of multi-pass membrane proteins. Here, we report two patients born to a consanguineous family with a novel loss-of-function variant; (NM_001242597.2:c.193-197del) in TMEM147 causing intellectual disability and spasticity. Whole exome sequencing and validating Sanger sequencing were utilized to confirm the identified causal variant. Our findings were in line with the previously described patients with TMEM147 variants manifesting intellectual disability as a major clinical sign but also featured spasticity as a phenotypic expansion. This study provides additional evidence for the pathogenicity of TMEM147 mutations in intellectual disability and expands the phenotypic and variant spectrum linked to this gene.

Mutational spectrum of DNA damage and mismatch repair genes in prostate cancer.

Over the past few years, a number of studies have revealed that a significant number of men with prostate cancer had genetic defects in the DNA damage repair gene response and mismatch repair genes. Certain of these modifications, notably gene alterations known as homologous recombination (HRR) genes; PALB2, CHEK2 BRCA1, BRCA2, ATM, and genes for DNA mismatch repair (MMR); MLH1, MSH2, MSH6, and PMS2 are connected to a higher risk of prostate cancer and more severe types of the disease. The DNA damage repair (DDR) is essential for constructing and diversifying the antigen receptor genes required for T and B cell development. But this DDR imbalance results in stress on DNA replication and transcription, accumulation of mutations, and even cell death, which compromises tissue homeostasis. Due to these impacts of DDR anomalies, tumor immunity may be impacted, which may encourage the growth of tumors, the release of inflammatory cytokines, and aberrant immune reactions. In a similar vein, people who have altered MMR gene may benefit greatly from immunotherapy. Therefore, for these treatments, mutational genetic testing is indicated. Mismatch repair gene (MMR) defects are also more prevalent than previously thought, especially in patients with metastatic disease, high Gleason scores, and diverse histologies. This review summarizes the current information on the mutation spectrum and clinical significance of DDR mechanisms, such as HRR and MMR abnormalities in prostate cancer, and explains how patient management is evolving as a result of this understanding.

Neurodevelopmental disorder and immunodeficiency

Background: Neurodevelopment is closely entwined with immune maturation and function during embryogenesis. While haematopoietic-derived microglia have recognized roles in a number of neurodevelopmental processes, the contribution of molecules classically involved in the immune system (including complement, toll-like receptors, and cytokines) are also emerging. To date, approximately 11% of genes known to cause primary immunodeficiency also confer varying degrees of neurological abnormalities. These can range from intellectual disability, cognitive and behavioural disorders, through to seizures, spasticity, and motor development delay. However, very rarely are sensory processing defects associated with aberrations of the immune system. Aims: To define the clinical presentation and immune phenotype of a novel syndrome encompassing immunodeficiency, neurodevelopmental abnormalities, and altered pain sensitivity in two siblings. Methods: Comprehensive retrospective review of the patient’s charts were performed, in accordance with local research ethics board approval. Results: We describe two teenage sisters who presented with recurrent sinopulmonary infections, lymphopenia affecting both B and T cells, developmental delay, learning and processing disorder, seizures, and reduced sensitivity to pain. Other features include bronchogenic cyst, microscopic hematuria, oral ulcers, papular urticaria, and keratosis pilaris. Conclusion: An underlying defect in genes known to cause primary immunodeficiency was not identified, suggesting the role of an as-yet undefined molecule at the crossroads of immunity, neurodevelopment, and sensory processing. Statement of novelty: We report on two patients, siblings, with a novel phenotype of combined immunodeficiency, neurodevelopmental delay, and reduced sensitivity to painful stimuli.

A unique case of rectal cancer with coexistence of multiple pathways of carcinogenesis

BackgroundColorectal cancer with a global incidence of 10% has multiple pathways implicated in its carcinogenesis. WNT signaling is the principal underlying pathway via APC gene, while defective mismatch repair genes and epigenetic changes also are known to contribute.Case presentationHere, we present an unusual case of rectal adenocarcinoma in a woman, with germline MSH6 and PMS1 mutations, and simultaneous somatic APC and TP53 mutations treated with surgery and adjuvant capecitabine.ConclusionsThe case is unique suggesting a possible interaction between the two pathways and contributing to carcinogenesis in this patient. This also suggests need for a thorough germline and somatic mutation evaluation in select colorectal cancer patients to direct a tailored therapy.

Characterization of infectious and non-infectious gastrointestinal disease in common variable immunodeficiency: analysis of 114 patient cohort.

Common Variable Immunodeficiency (CVID), a complex primary immunodeficiency syndrome defined by defective B cell responses to infection and vaccination, has heterogeneous clinical manifestations. Gastrointestinal (GI) complications in CVID, both infectious and non-infectious, can cause significant impairment leading to malabsorption and frank malnutrition. In order to better characterize the spectrum of GI disease associated with CVID, we describe 114 patients with GI disease (15.6%) from our 728 patient single center CVID cohort. Norovirus, Giardia and Cytomegalovirus were the most frequently isolated infectious pathogens. CVID enteropathy was the most encountered GI diagnosis based on endoscopy, with only a minority of patients having Crohn's disease (6.1%) or ulcerative colitis/proctitis (4.5%). Concurrent autoimmunity (30.7%), lung disease (18.4%) and malignancy (8.7%) were also present in significant proportion of subjects. Lastly, 16 of 47 (34%) who underwent whole exome sequencing demonstrated a culprit gene defect associated with CVID.

The microtubule signature in cardiac disease: etiology, disease stage, and age dependency

Employing animal models to study heart failure (HF) has become indispensable to discover and test novel therapies, but their translatability remains challenging. Although cytoskeletal alterations are linked to HF, the tubulin signature of common experimental models has been incompletely defined. Here, we assessed the tubulin signature in a large set of human cardiac samples and myocardium of animal models with cardiac remodeling caused by pressure overload, myocardial infarction or a gene defect. We studied levels of total, acetylated, and detyrosinated α-tubulin and desmin in cardiac tissue from hypertrophic (HCM) and dilated cardiomyopathy (DCM) patients with an idiopathic (n = 7), ischemic (n = 7) or genetic origin (n = 59), and in a pressure-overload concentric hypertrophic pig model (n = 32), pigs with a myocardial infarction (n = 28), mature pigs (n = 6), and mice (n = 15) carrying the HCM-associated MYBPC32373insG mutation. In the human samples, detyrosinated α-tubulin was increased 4-fold in end-stage HCM and 14-fold in pediatric DCM patients. Acetylated α-tubulin was increased twofold in ischemic patients. Across different animal models, the tubulin signature remained mostly unaltered. Only mature pigs were characterized by a 0.5-fold decrease in levels of total, acetylated, and detyrosinated α-tubulin. Moreover, we showed increased desmin levels in biopsies from NYHA class II HCM patients (2.5-fold) and the pressure-overload pig model (0.2–0.3-fold). Together, our data suggest that desmin levels increase early on in concentric hypertrophy and that animal models only partially recapitulate the proliferated and modified tubulin signature observed clinically. Our data warrant careful consideration when studying maladaptive responses to changes in the tubulin content in animal models.Graphical

Hearing Impairment and Neuroimaging Results in Mitochondrial Diseases.

Mitochondrial diseases (MDs) are heterogeneous genetic disorders characterized by mitochondrial DNA (mtDNA) defects, involving tissues highly dependent on oxidative metabolism: the inner ear, brain, eye, skeletal muscle, and heart. We describe adult patients with genetically defined MDs, characterizing hearing function and neuroimaging results. We enrolled 34 patients (mean age: 50.02 ± 15 years, range: 18-75 years; 20 females and 14 males) classified in four groups: MELAS, MIDD, PEO, and Encephalopathy/Polyneuropathy. Audiological evaluations included psychoacoustical tests (pure-tone and speech audiometry), electrophysiological tests (Auditory Brainstem Responses, ABRs), and Impedenzometry. Neuroimaging evaluations considered global MRI abnormalities or structural brain changes. In total, 19/34 patients carried the m.3243A > G mutation (6 affected by MELAS, 12 affected by MIDD, and 1 affected by PEO); 11 had an mtDNA deletion (all affected by PEO); 3 had nuclear genes associated with MDs (POLG1 and OPA1); and 1 patient had an mtDNA deletion without an identified nuclear gene defect (affected by PEO). Sensory neural, bilateral, and symmetrical hearing loss was present in 25 patients (73.5%) to different degrees: 9 mild, 9 moderate, 5 severe, and 2 profound. The severe/profound and mild hearing losses were associated with pantonal and high-frequency audiograms, respectively. Instead, moderate hearing losses were associated with both high-frequency (five cases) and pantonal (five cases) audiogram shapes. In addition, 21/25 patients showed a cochlear site of lesion (84%), and 4/25 (16%) showed a retrocochlear site. We found global MRI abnormalities or structural brain changes in 26/30 subjects (86.6%): 21 had white matter abnormalities, 15 had cortical atrophy, 10 had subcortical atrophy, 8 had basal nuclei involvement or cerebellar atrophy, 4 had stroke-like lesions or laminar necrosis, and 1 had cysts or vacuolated lesions. We concluded that genetic alterations are associated with different clinical presentations for both auditory function and neuroradiological findings. There is no fixed relationship between genotype and phenotype for the clinical conditions analyzed.

MRNA splicing is modulated by intronic microRNAs

Splicing of transcripts is catalyzed by the spliceosome, a mega-complex consisting of hundreds of proteins and five snRNAs, which employs direct interactions. When U1 snRNA forms high-affinity binding, namely more than eight base pairs, with the 5'SS, the result is usually a suppressing effect on the splicing activity. This likely occurs due to the inefficient unwinding of U1/5'SS base-pairing or other regulatory obstructions. Here, we show invitro and in patient-derived cell lines that pre-microRNAs can modulate the splicing reaction by interacting with U1 snRNA. This leads to reduced binding affinity to the 5'SS, and hence promotes the inclusion of exons containing 5'SS, despite sequence-based high affinity to U1. Application of the mechanism resulted in correction of the splicing defect in the disease-causing VCAN gene from an individual with Wagner syndrome. This pre-miRNA/U1 interaction can regulate the expression of alternatively spliced exons, thus extending the scope of mechanisms regulating splicing.

The Black Death ravaging Europe in the fourteenth century might be the pathogen-driven selective pressure for factor V Leiden

Factor V Leiden as a mutant gene defect of hereditary thrombophilia exists peculiarly in Caucasians but almost absent in people traditionally living in Asia. This lopsided dispensation has persisted as an enigma to be solved. Thus, a hypothesis is raised here that the Black Death, a plague pandemic caused by Yersinia pestis, which ravaged Europe in the fourteenth century and brought on a severe human extermination constituted the pathogenic selective pressure for factor V Leiden of which the procoagulative, anti-fibrinlolysis function, and the resultant resistance potential to Yersinia pestis infection have been demonstrated in a series of animal experiments and clinical observation. The same explanation is also proposed for a similar unbalanced distribution of prothrombin G20210A mutation, another thrombophilia genetic variant, between Caucasians and Asians despite awaiting more solid evidence in the near future. On the other hand, the fact that deficiency of protein C, protein S, and antithrombin had not risen during the plague disaster is theoretically attributed to more severe and fatal disseminated intravascular coagulation associated with the dysfunction of them. The whole assumption implies an underlying evolutionary advantage of factor V Leiden and a mysterious relationship between genetic traits and diseases. It is hoped that future investigations dedicating to analysis of ancient DNA from human remains in the medieval cemeteries before, during, and after the plague will finally let the speculation come true.

Brugada syndrome is still a current clinical problem. What do we know today - a literature review

Brugada syndrome (BrS) is a rare congenital arrhythmia syndrome. BrS is characterized by a tendency to syncope, ventricular arrhythmias and sudden cardiac death. These symptoms occur mainly at night and can occur spontaneously or as a result of provocation by, for example, fever, stress or medication. Based on the differences in electrocardiography, three types were distinguished. Genetic studies are being conducted, which have shown a significant defect of the SCN5A gene, which in turn leads to disturbances in the functioning of the sodium channel NaV1.5 has a negative impact on the course of depolarization of myocardial cells. Patients with symptoms of the disease are subjected to implantation of a cardioverter-defibrillator, which protects them against sudden death. Data was obtained from the PubMed and Google Scholar platforms.

Spinal Muscle Atrophy (SMA) in a 5 Years Old Girl from Macedonia: Case Report

Spinal muscular atrophies are inherited diseases in which nerve cells in the spinal cord and brainstem regress, causing progressive muscle weakness and wasting. There are five main types of spinal muscular atrophy, which are classified according to the severity of muscle weakness and wasting. Depending on the type, one may be confined to a wheelchair, and life expectancy may also be limited. Based on symptoms, the diagnosis can be proven through family history, muscle and nerve function studies, and blood tests to determine the location of the defective gene. Spinal muscular atrophies are usually inherited in an autosomal recessive manner. Thus, for a person to inherit the disease, two genes are necessary, one from each parent. The group of SMA disease in childhood can affect the brain and spinal cord as well as the peripheral nerves. We present a case of a 5 years old girl with spinal muscle atrophy and analyze the different new therapeutical options and future research in the field of spinal muscular atrophy in childhood.

An inactivating human TRPC6 channel mutation without focal segmental glomerulosclerosis

Transient receptor potential cation channel-6 (TRPC6) gene mutations cause familial focal segmental glomerulosclerosis (FSGS), which is inherited as an autosomal dominant disease. In patients with TRPC6-related FSGS, all mutations map to the N- or C-terminal TRPC6 protein domains. Thus far, the majority of TRPC6 mutations are missense resulting in increased or decreased calcium influx; however, the fundamental molecular mechanisms causing cell injury and kidney pathology are unclear. We report a novel heterozygous TRPC6 mutation (V691Kfs*) in a large kindred with no signs of FSGS despite a largely truncated TRPC6 protein. We studied the molecular effects of V691Kfs* TRPC6 mutant using the tridimensional cryo-EM structure of the tetrameric TRPC6 protein. The results indicated that V691 is localized at the pore-forming transmembrane region affecting the ion conduction pathway, and predicted that V691Kfs* causes closure of the ion-conducting pathway leading to channel inactivation. We assessed the impact of V691Kfs* and two previously reported TRPC6 disease mutants (P112Q and G757D) on calcium influx in cells. Our data show that the V691Kfs* fully inactivated the TRCP6 channel-specific calcium influx consistent with a complete loss-of-function phenotype. Furthermore, the V691Kfs* truncation exerted a dominant negative effect on the full-length TRPC6 proteins. In conclusion, the V691Kfs* non-functional truncated TRPC6 is not sufficient to cause FSGS. Our data corroborate recently characterized TRPC6 loss-of-function and gain-of-function mutants suggesting that one defective TRPC6 gene copy is not sufficient to cause FSGS. We underscore the importance of increased rather than reduced calcium influx through TRPC6 for podocyte cell death.

Whole exome sequencing reveals a missense mutation in the ADA gene causing severe combined immune deficiency in a Pakistani family ADA gene mutation causing SCID

BACKGROUND &amp; OBJECTIVE: Human adenosine deaminase deficiency, OMIM 102700 (ADA deficiency) is a genetic disorder which causes severe combined immunodeficiency (SCID). The enzyme adenosine deaminase is a housekeeping in nature and is involved in purine catabolism by catalyzing irreversible deamination of adenosine and deoxyadenosine. The SCID patients’ immune system is unable to fight off most of the bacterial and fungal infections due to profound lymphopenia (T-B-NK+). About 20% of the SCID patients are genetically homozygous for defective ADA gene. In our study we aimed to find out genetic variant in ADA gene in a family carrying severe combined immune deficiency. Objective in the current study is to unravel and characterize the molecular cause of the patient suffering from by birth SCID.&#x0D; METHODOLOGY: In the present study we enrolled a 6-month-old female SCID patient belonging to highly consanguineous Pakistani family. Patient clinical features included repeated chest infection with failure to thrive, fever and chronic diarrhea. Whole blood samples from patient, parents and healthy siblings were acquired in EDTA tubes. DNA was extracted from all the blood samples.&#x0D; RESULTS: Flowcytometry revealed lymphopenia (T-B-NK+) type of SCID. Whole Exome Sequencing (WES) identified a one nucleotide change (c.716G&gt;A) in ADA gene exon 8. The segregation of the identified variant in the family was confirmed through Sanger Sequencing.&#x0D; CONCLUSION: In this study, we presented detailed clinical and genetic description of patient suffering from severe combined immune deficiency. The immunological and genetic findings presented in this study will facilitate early diagnosis of the disease. Segregation of the identified variant in the family members will also aid in genetic counseling the family.

Detection of NCF-1 Gene Expression as a Diagnostic Tool for Autosomal Recessive Chronic Granulomatous Disease among Egyptian Children with Phagocytic Dysfunction

Abstract Background Chronic granulomatous disease (CGD) is an inherited primary immunodeficiency disorder caused by functional impairment of the nicotinamide dinucleotide phosphate (NADPH) oxidase complex in neutrophilic granulocytes and monocytes and characterized by recurrent and severe infections, dysregulated inflammation and autoimmunity. Aim of the Work To diagnose the autosomal recessive (AR) type of CGD among a group of Egyptian pediatric patients with phagocytic dysfunction by detection of Neutrophil Cytosolic Factor-1 (NCF-1) gene expression using reverse transcription polymerase chain reaction (RT-PCR) and to correlate it with other diagnostic tests. Subjects and Methods A case-control study was conducted on 15 provisionally diagnosed CGD pediatric patients (Group I) by the use of DHR test, with the stimulation index using PMA &amp;lt; 30%. They were recruited from different university hospitals in Egypt. The study also included 12 mothers of the studied patients to detect the genetic mutations in carriers, if any, (Group II) and 14 apparently healthy children as a control group (Group III). Full medical history was taken and thorough clinical examination was done. The selected groups underwent testing for phagocytic and lytic indices, measurement of NCF-1 gene expression by real time RT-PCR. Results The comparative statistics between group I and group III as regards the phagocytic index (PI) revealed a high statistical significant difference between both groups. In addition, a statistically significant difference between both groups as regards lytic index (LI) was also revealed. Correlation studies were done between fold change of NCF-1 gene expression and each of PI, LI and DHR and showed no significant statistical correlation between these parameters in the 3 studied groups. Cases with a fold change of NCF-1 gene expression less than 0.48 (cut-off value calculated by the 25th percentile fold change of the control group), are considered having defective NCF-1 gene expression. At this cut-off value 2 out of 15 CGD cases and 3 mothers out of 12 showed NCF-1 gene under-expression. Conclusion Assessment of NCF-1 gene expression which encodes p47phox by real time RT- PCR in the present study could detect defective gene expression only among two CGD children and their mother as well as two other mothers with no correlation to other studied parameters. Since CGD is a genotypically heterogeneous disease; the findings of the present study highlight the importance of molecular testing for diagnosis after screening for NADPH oxidase protein deficiency by flow cytometry.

Detection of CYBA Gene Expression by Reverse Transcription PCR as a Diagnostic Tool for Autosomal Recessive Chronic Granulomatous Disease in a Sample of Egyptian Children

Abstract Chronic granulomatous disease (CGD) is an inherited primary immunodeficiency disease caused by functional impairment of the nicotinamide dinucleotide phosphate (NADPH) oxidase complex in neutrophilic granulocytes and monocytes, characterized by recurrent and severe infections, dysregulated inflammation, and autoimmunity. Approximately two-thirds of patients with CGD have defects in Cytochrome Bβ (CYBB), the X-linked gene encoding glycoprotein 91 phagocytic oxidase (gp91phox). Rarer autosomal recessive (AR) forms of CGD are caused by autosomal recessive mutations in CYBA genes encoding protein 22 phagocytic oxidase (p22phox). However, the incidence of autosomal recessive CGD can be higher than X-linked CGD in countries with high rates of consanguineous marriage. In the present study we aimed to diagnose the commonest AR-type of CGD by detection of CYBA gene expression using real time RT-PCR as a cheaper diagnostic method for CGD subtypes categorization among immunodeficient children. This case-control study was conducted on 15 children provisionally diagnosed as CGD patients with DHR stimulation index using phorbol myristate acetate (PMA) &amp;lt; 30% (Group I). The study also included 12 mothers and 8 fathers of the studied patients to detect the genetic mutations in carriers, if any (Group IIa and IIb respectively), and 14 apparently healthy children as a control group (Group III). We found that cases with a fold change of CYBA gene expression less than 0.6 were considered under-expressed. At this cut-off value, from our molecularly studied subjects 1 case and 2 mothers showed under-expression of CYBA gene. In conclusion, we could establish the diagnosis of AR-form of CGD, derives from defects in the CYBA gene, which encodes p22phox of the NADPH oxidase using real time RT-PCR, without the need to use complex and expensive methodologies such as northern blot, slot blot, or genomic DNA sequencing.

Detection of NCF-2 Gene Expression in Egyptian Children with Chronic Granulomatous Disease

Abstract Background Chronic granulomatous disease (CGD) is a rare inherited primary immunodeficiency disorder (PID) which is characterized by enhanced susceptibility to severe bacterial and fungal infections. It results from defects in one of the five polypeptide subunits of the nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) complex; CYBB (gp91-phox), NCF-1 (p47phox), CYBA (p22-phox), NCF-2 (p67-phox), or NCF-4 (p40-phox) with a resulting failure of the phagocytes in generating a variety of microbicidal reactive oxygen radicals during respiratory burst. Objectives This work intended to diagnose autosomal recessive (AR)-type of CGD by detection of NCF-2 gene expression using real time RT-PCR as a cheaper diagnostic method for CGD subtypes categorization among CGD children. Subjects and methods This case-control study was conducted on 15 children provisionally diagnosed as CGD patients by the use of dihydrorhodamine (DHR) stimulation index (Group I) in addition to 12 mothers and 8 fathers of the studied patients (Group IIa and IIb respectively) to detect the genetic mutations in carriers, if any, and 14 apparently healthy children as a control group (Group III). In the present study, cases with a fold change of NCF-2 gene expression less than 0.67 were considered defective for NCF-2 gene expression. At this cut-off value, from our molecularly studied subjects, 2 CGD cases and one mother showed underexpression of NCF-2 gene. In conclusion, defect in the NCF-2 gene, which encodes gp67-phox of the oxidase enzyme could be done by RT-PCR as a cheaper diagnostic method for CGD without the need to use complex and expensive methodologies such as northern blot, or genomic DNA sequencing.

Emerging and potential use of CRISPR in human liver disease.

CRISPR is a gene editing tool adapted from naturally occurring defense systems from bacteria. It is a technology that is revolutionizing the interrogation of gene functions in driving liver disease, especially through genetic screens and by facilitating animal knockout and knockin models. It is being used in models of liver disease to identify which genes are critical for liver pathology, especially in genetic liver disease, hepatitis, and in cancer initiation and progression. It holds tremendous promise in treating human diseases directly by editing DNA. It could disable gene function in the case of expression of a maladaptive protein, such as blocking transthyretin as a therapy for amyloidosis, or to correct gene defects, such as restoring the normal functions of liver enzymes fumarylacetoacetate hydrolase or alpha-1 antitrypsin. It is also being studied for treatment of hepatitis B infection. CRISPR is an exciting, evolving technology that is facilitating gene characterization and discovery in liver disease and holds the potential to treat liver diseases safely and permanently.

New GABA-Targeting Therapies for the Treatment of Seizures and Epilepsy: I. Role of GABA as a Modulator of Seizure Activity and Recently Approved Medications Acting on the GABA System.

γ-Aminobutyric acid (GABA) is the most prevalent inhibitory neurotransmitter in the mammalian brain and has been found to play an important role in the pathogenesis or the expression of many neurological diseases, including epilepsy. Although GABA can act on different receptor subtypes, the component of the GABA system that is most critical to modulation of seizure activity is the GABAA-receptor-chloride (Cl-) channel complex, which controls the movement of Cl- ions across the neuronal membrane. In the mature brain, binding of GABA to GABAA receptors evokes a hyperpolarising (anticonvulsant) response, which is mediated by influx of Cl- into the cell driven by its concentration gradient between extracellular and intracellular fluid. However, in the immature brain and under certain pathological conditions, GABA can exert a paradoxical depolarising (proconvulsant) effect as a result of an efflux of chloride from high intracellular to lower extracellular Cl- levels. Extensive preclinical and clinical evidence indicates that alterations in GABAergic inhibition caused by drugs, toxins, gene defects or other disease states (including seizures themselves) play a causative or contributing role in facilitating or maintaning seizure activity. Conversely, enhancement of GABAergic transmission through pharmacological modulation of the GABA system is a major mechanism by which different antiseizure medications exert their therapeutic effect. In this article, we review the pharmacology and function of the GABA system and its perturbation in seizure disorders, and highlight how improved understanding of this system offers opportunities to develop more efficacious and better tolerated antiseizure medications. We also review the available data for the two most recently approved antiseizure medications that act, at least in part, through GABAergic mechanisms, namely cenobamate and ganaxolone. Differences in the mode of drug discovery, pharmacological profile, pharmacokinetic properties, drug-drug interaction potential, and clinical efficacy and tolerability of these agents are discussed.