Challenges in Treating Genodermatoses: New Therapies at the Horizon

Genodermatoses are rare inherited skin diseases that frequently affect other organs. They often have marked effects on wellbeing and may cause early death. Progress in molecular genetics and translational research has unravelled many underlying pathological mechanisms, and in several disorders with high unmet need, has opened the way for the introduction of innovative treatments. One approach is to intervene where cell-signaling pathways are dysregulated, in the case of overactive pathways by the use of selective inhibitors, or when the activity of an essential factor is decreased by augmenting a molecular component to correct disequilibrium in the pathway. Where inflammatory reactions have been induced by a genetically altered protein, another possible approach is to suppress the inflammation directly. Depending on the nature of the genodermatosis, the implicated protein or even on the particular mutation, to correct the consequences or the genetic defect, may require a highly personalised stratagem. Repurposed drugs, can be used to bring about a “read through” strategy especially where the genetic defect induces premature termination codons. Sometimes the defective protein can be replaced by a normal functioning one. Cell therapies with allogeneic normal keratinocytes or fibroblasts may restore the integrity of diseased skin and allogeneic bone marrow or mesenchymal cells may additionally rescue other affected organs. Genetic engineering is expanding rapidly. The insertion of a normal functioning gene into cells of the recipient is since long explored. More recently, genome editing, allows reframing, insertion or deletion of exons or disruption of aberrantly functioning genes. There are now several examples where these stratagems are being explored in the (pre)clinical phase of therapeutic trial programmes. Another stratagem, designed to reduce the severity of a given disease involves the use of RNAi to attenuate expression of a harmful protein by decreasing abundance of the cognate transcript. Most of these strategies are short-lasting and will thus require intermittent life-long administration. In contrast, insertion of healthy copies of the relevant gene or editing the disease locus in the genome to correct harmful mutations in stem cells is more likely to induce a permanent cure. Here we discuss the potential advantages and drawbacks of applying these technologies in patients with these genetic conditions. Given the severity of many genodermatoses, prevention of transmission to future generations remains an important goal including offering reproductive choices, such as preimplantation genetic testing, which can allow selection of an unaffected embryo for transfer to the uterus.

Riboswitch RS thiT as a molecular tool in Lactococcus lactis

Previous RNA sequencing has allowed identifying 129 long 5'-UTRs in the L. lactis MG1363 transcriptome. These sequences potentially harbor cis -acting riboswitches. One of the identified extended 5'-UTRs is a putative thiamine pyrophosphate (TPP) riboswitch. It is located immediately upstream of the thiamine transporter gene thiT ( llmg_0334 ). To confirm this assumption, the 5'-UTR sequence was placed upstream of the gene encoding the super folder green fluorescent protein, sfgfp , allowing examining the expression of sfGFP in the presence or absence of thiamine in the medium. The results show that this sequence indeed represents a thiamine-responsive TPP riboswitch. This RNA-based genetic control device was used to successfully restore the mutant phenotype of an L. lactis strain lacking the major autolysin gene acmA . The L. lactis thiT TPP riboswitch (RS thiT ) is a useful molecular genetic tool enabling to gradually downregulate the expression of genes under its control by adjusting thiamine concentration. Importance The capacity of microbes with biotechnological importance to adapt and survive under quickly changing industrial conditions depends on their ability to adequately control gene expression. Riboswitches are important RNA-based elements involved in rapid and precise gene regulation. Here we present the identification of a natural thiamine-responsive riboswitch of Lactococcus lactis , a bacterium used worldwide in the production of dairy products. We used it to restore a genetic defect in an L. lactis mutant and show that it is a valuable addition to the ever-expanding L. lactis genetic toolbox.

Case Report: A New Gain-of-Function Mutation of STAT1 Identified in a Patient With Chronic Mucocutaneous Candidiasis and Rosacea-Like Demodicosis: An Emerging Association

PurposeHeterozygous missense STAT1 mutations leading to a gain of function (GOF) are the most frequent genetic cause of chronic mucocutaneous candidiasis (CMC). We describe the case of a patient presenting a new GOF mutation of STAT1 with the clinical symptoms of CMC, recurrent pneumonia, and persistent central erythema with papulopustules with ocular involvement related to rosacea-like demodicosis.MethodsGenetic analysis via targeted next-generation sequencing (NGS; NGS panel DIPAI v.1) exploring the 98 genes most frequently involved in primary immunodeficiencies, including STAT1, was performed to identify an underlying genetic defect.ResultsNGS identified a novel variant of STAT1, c.884C>A (exon 10), p.T295Y, not previously described. This variant was found to be gain of function using an in vitro luciferase reporter assay. Rosacea-like demodicosis was confirmed by substantial Demodex proliferation observed via the microscopic examination of a cutaneous sample. A review of literature retrieved 20 other cases of STAT1 GOF mutations associated with early-onset rosacea-like demodicosis, most with ocular involvement.ConclusionWe describe a new STAT1 GOF mutation associated with a phenotype of CMC and rosacea-like demodicosis. Rosacea-like demodicosis appears as a novel and important clinical phenotype among patients with STAT1 GOF mutation.

CLASSIC FINDING OF DANDY-WALKER MALFORMATION- CASE REPORT

Summary: The frequency and importance of posterior fossa evaluation has increased signicantly in the last 20 years due to advances in neuroimaging. Today, conventional and advanced neuroimaging techniques allow a detailed assessment of the complex anatomical structures within the posterior fossa. A wide spectrum of congenital anomalies (anomalies due to an alteration of the primary developmental program caused by a genetic defect) and due to the breakdown of a structure that had a potential for normal development has been demonstrated. Knowledge of the spectrum of congenital anomalies of the posterior fossa and its well-dened diagnostic criteria is essential for optimal therapy, an accurate prognosis, and correct genetic counseling. Objective: Analyze the importance of the precise diagnosis of congenital anomalies of the posterior fossa, emphasizing Dandy Walker syndrome, through a clinical case. Design: Prospective, observational in a single center. Methodology: This is a systematic review, Dandy Walker syndrome, detailing its clinical characteristics and short-term complications. The information and images obtained belong to the medical personnel in charge of the case, whose reinforcements are provided by the Excel, Word and JPG statistical package.

Evaluation of MicroRNA-125b-5p and Transcription Factors BLIMP1 and IRF4 Expression in Unsolved Common Variable Immunodeficiency Patients

Common variable immunodeficiency (CVID) is the most prevalent form of symptomatic primary humoral immunodeficiencies characterized by failure in the final differentiation of B lymphocytes. The majority of CVID cases have no identified genetic defect, and epigenetic alteration could be involved in the pathogenesis of CVID. Hence, we aimed to evaluate the expression of hsa-miR-125b-5p -and, B lymphocyte-induced maturation protein-1(BLIMP-1) and interferon regulatory protein-4 (IRF-4) in a group of CVID patients with no definitive genetic diagnosis in comparison with healthy individuals. Ten CVID patients (all known genes excluded) and 10 age and sex-matched healthy controls participated in the study. B lymphocytes were isolated and expression of miR-125b-5p, IRF4, and BLIMP1 were evaluated by real-time polymerase chain reaction (RT-PCR). Moreover, B cell subsets were analyzed by flow cytometry. The results showed that the relative expression of miR-125b-5p in CVID patients was increased while it was decreased for the BLIMP1 and IRF4 transcription factors compared with the healthy controls. Although a reduction was observed in switched and non-switched memory B cells among all high-miR patients, these subsets were decreased in patients with normal miR expression (71.0% and 85.0%, respectively). Our results suggest that overexpression of miR-125b-5p affects the terminal differentiation of B cells in a selected group of CVID patients by downregulating the BLIMP-1 gene and more intensively for the IRF-4 gene expressions.

Article on Tay-Sachs Disease

Tay–Sachs disease is a genetic disorder that results in the destruction of nerve cells in the brain and spinal cord..also known as GM2 gangliosidosis or Hexosaminidase A deficiency) is an autosomal recessive genetic disorder. In its most common variant known as infantile Tay-Sachs disease it presents with a relentless deterioration of mental and physical abilities which commences at 6 months of age and usually results in death by the age of four.It is caused by a genetic defect in a single gene with one defective copy of that gene inherited from each parent. The disease occurs when harmful quantities of gangliosides accumulate in the nerve cells of the brain, eventually leading to the premature death of those cells. There is currently no cure or treatment. Tay- Sachs disease is a rare disease. Other autosomal disorders such as cystic fibrosis and sickle cell anemia are far more common. TSD is an autosomal recessive genetic disorder, meaning that when both parents are carriers, there is a 25% risk of giving birth to an affected child.

Risk factors for death in Welsh infants with a congenital anomaly

ObjectivesTo investigate risk factors associated with death of infants with a congenital anomaly in Wales, UK.DesignA population-based cohort study.SettingData from the Welsh Congenital Anomaly Register and Information Service (CARIS) linked to live births and deaths from the Office for National Statistics.PatientsAll live births between 1998 and 2016 with a diagnosis of a congenital anomaly, which was defined as a structural, metabolic, endocrine or genetic defect, as well as rare disease of hereditary origin.Main outcome measuresAdjusted ORs (aORs) were estimated for socio-demographic, maternal, infant and intervention factors associated with death in infancy, using logistic regression for all, isolated, multiple and cardiovascular anomalies.Results30 424 live births affected by congenital anomalies were identified, including 1044 infants who died by the age of 1 year (infant mortality rate: 16.5 per 10 000 live births, case fatality: 3.4%, 30.3% of all infant deaths). Risk factors for infant death were non-white versus white ethnicity (aOR: 2.25; 95% CI: 1.77–2.86); parous versus nulliparous (aOR: 1.24; 95% CI: 1.08–1.41); smoking during pregnancy versus non-smokers/ex-smokers (aOR: 1.20; 95% CI: 1.02–1.40); preterm versus term birth (aOR: 4.38; 95% CI 3.86–4.98); female versus male infants (aOR: 1.28; 95% CI: 1.13–1.46) and the earlier years of the birth cohort (aOR: 0.96; 95% CI: 0.95–0.98 per yearly increase). Infants with a cardiovascular anomaly who received surgery had a lower odds of death than those who did not (aOR: 0.34; 95% CI: 0.15–0.75). Preterm birth was a significant factor for death for all anomalies but the effect of the other characteristics varied according to anomaly group.ConclusionsNearly a third of all infant deaths had an associated anomaly. Improving access to prenatal care, smoking cessation advice, optimising care for preterm infants and surgery may help lower the risk of infant death.

Probability of manifestation of fertility haplotype AH1 in tested ayrshire bulls

The aim of the research is to study the probability of manifestation of the haplotype of fertility AH1 in Ayrshire sires with different variants of the presence of AH1C in male ancestors in the first four rows of their pedigree.Materials and methods. The material of the study was the data of the electronic database created at RRIFAGB on the presence of the haplotype AH1 in 74 sire of the Ayrshire breed of Russia, of which 22 are carriers of the genetic defect - AH1C, and the rest are free - AH1F. To find patterns in the manifestation of the haplotype in the tested bulls, we analyzed different variants of the presence of AH1C in male ancestors in four rows of the paternal and maternal sides of their pedigree with the calculation of the probability of its manifestation. The study used data from the electronic databases “Card file of Ayrshire bulls” and “Card file of mothers of Ayrshire bulls” prepared for selection and genetic analysis using the computer program “SGS-VNIIGRZH“ and data from the Canadian website www.cdn.ca. The strength of the influence of the factors "distance of the nearest carrier ancestor" and "number of carrier ancestors" in all ranks of the proband's pedigrees on the manifestation of the haplotype AH1 in bulls of the Ayrshire breed was calculated using ANOVA in Data Analysis of Microsoft Office Excel.Results. Among the tested livestock, 42.3% of bulls AH1F did not have male ancestors of AH1C in the pedigree, while AH1C bulls had 27.3% of them. It was found that with the nearest ancestor AH1C in the 4th row of the pedigree, the haplotype was manifested in only 8.3% of the tested sires, in the 3rd and 2nd rows - in 16.7%, and in the 1st - in 75.0%. The strength of the factor “distance of the nearest carrier ancestor” is 22.0%, while the factor “number of carrier ancestors” in all ranks of the proband's pedigrees is 21.0%. Ancestors of AH1С in the first two rows of the pedigree is a reliable indicator for identifying the fertility haplotype in a proband. The highest probability of manifestation of the AH1 in a proband is observed in the presence of carrier ancestors on both sides of the pedigree, including the father.Conclusion. To reduce the likelihood of manifestation of AH1 in a proband, it is necessary to prevent the presence of bulls carrying the fertility haplotype closer to the fourth row in his pedigree, and also to avoid in all ranks of the pedigree more than three AH1C males.

Genetic epidemiology of autoinflammatory disease variants in Indian population from 1029 whole genomes

Background Autoinflammatory disorders are the group of inherited inflammatory disorders caused due to the genetic defect in the genes that regulates innate immune systems. These have been clinically characterized based on the duration and occurrence of unprovoked fever, skin rash, and patient’s ancestry. There are several autoinflammatory disorders that are found to be prevalent in a specific population and whose disease genetic epidemiology within the population has been well understood. However, India has a limited number of genetic studies reported for autoinflammatory disorders till date. The whole genome sequencing and analysis of 1029 Indian individuals performed under the IndiGen project persuaded us to perform the genetic epidemiology of the autoinflammatory disorders in India. Results We have systematically annotated the genetic variants of 56 genes implicated in autoinflammatory disorder. These genetic variants were reclassified into five categories (i.e., pathogenic, likely pathogenic, benign, likely benign, and variant of uncertain significance (VUS)) according to the American College of Medical Genetics and Association of Molecular pathology (ACMG-AMP) guidelines. Our analysis revealed 20 pathogenic and likely pathogenic variants with significant differences in the allele frequency compared with the global population. We also found six causal founder variants in the IndiGen dataset belonging to different ancestry. We have performed haplotype prediction analysis for founder mutations haplotype that reveals the admixture of the South Asian population with other populations. The cumulative carrier frequency of the autoinflammatory disorder in India was found to be 3.5% which is much higher than reported. Conclusion With such frequency in the Indian population, there is a great need for awareness among clinicians as well as the general public regarding the autoinflammatory disorder. To the best of our knowledge, this is the first and most comprehensive population scale genetic epidemiological study being reported from India.