Phenotypic characteristics of early Wolfram syndrome

BACKGROUND: Wolfram Syndrome (WFS:OMIM 222300) is an autosomal recessive, progressive, neurologic and endocrinologic degenerative disorder caused by mutations in the WFS1 gene, encoding the endoplasmic reticulum (ER) protein wolframin, thought to be involved in the regulation of ER stress. This paper reports a cross section of data from the Washington University WFS Research Clinic, a longitudinal study to collect detailed phenotypic data on a group of young subjects in preparation for studies of therapeutic interventions. METHODS: Eighteen subjects (ages 5.9–25.8, mean 14.2 years) with genetically confirmed WFS were identified through the Washington University International Wolfram Registry. Examinations included: general medical, neurologic, ophthalmologic, audiologic, vestibular, and urologic exams, cognitive testing and neuroimaging. RESULTS: Seventeen (94%) had diabetes mellitus with the average age of diabetes onset of 6.3 ± 3.5 years. Diabetes insipidus was diagnosed in 13 (72%) at an average age of 10.6 ± 3.3 years. Seventeen (94%) had optic disc pallor and defects in color vision, 14 (78%) had hearing loss and 13 (72%) had olfactory defects, eight (44%) had impaired vibration sensation. Enuresis was reported by four (22%) and nocturia by three (17%). Of the 11 tested for bladder emptying, five (45%) had elevated post-void residual bladder volume. CONCLUSIONS: WFS causes multiple endocrine and neurologic deficits detectable on exam, even early in the course of the disease. Defects in olfaction have been underappreciated. The proposed mechanism of these deficits in WFS is ER stress-induced damage to neuronal and hormone-producing cells. This group of subjects with detailed clinical phenotyping provides a pool for testing proposed treatments for ER stress. Longitudinal follow-up is necessary for establishing the natural history and identifying potential biomarkers of progression

A Reduction in Ribonucleotide Reductase Activity Slows Down the Chromosome Replication Fork but Does Not Change Its Localization

BACKGROUND:It has been proposed that the enzymes of nucleotide biosynthesis may be compartmentalized or concentrated in a structure affecting the organization of newly replicated DNA. Here we have investigated the effect of changes in ribonucleotide reductase (RNR) activity on chromosome replication and organization of replication forks in Escherichia coli. METHODOLOGY/PRINCIPAL FINDINGS:Reduced concentrations of deoxyribonucleotides (dNTPs) obtained by reducing the activity of wild type RNR by treatment with hydroxyurea or by mutation, resulted in a lengthening of the replication period. The replication fork speed was found to be gradually reduced proportionately to moderate reductions in nucleotide availability. Cells with highly extended C periods showed a "delay" in cell division i.e. had a higher cell mass. Visualization of SeqA structures by immunofluorescence indicated no change in organization of the new DNA upon moderate limitation of RNR activity. Severe nucleotide limitation led to replication fork stalling and reversal. Well defined SeqA structures were not found in situations of extensive replication fork repair. In cells with stalled forks obtained by UV irradiation, considerable DNA compaction was observed, possibly indicating a reorganization of the DNA into a "repair structure" during the initial phase of the SOS response. CONCLUSION/SIGNIFICANCE:The results indicate that the replication fork is slowed down in a controlled manner during moderate nucleotide depletion and that a change in the activity of RNR does not lead to a change in the organization of newly replicated DNA. Control of cell division but not control of initiation was affected by the changes in replication elongation

Reconstruction of major maternal and paternal lineages of the Cape Muslim population

The earliest Cape Muslims were brought to the Cape (Cape Town - South Africa) from Africa and Asia from 1652 to 1834. They were part of an involuntary migration of slaves, political prisoners and convicts, and they contributed to the ethnic diversity of the present Cape Muslim population of South Africa. The history of the Cape Muslims has been well documented and researched however no in-depth genetic studies have been undertaken. The aim of the present study was to determine the respective African, Asian and European contributions to the mtDNA (maternal) and Y-chromosomal (paternal) gene pool of the Cape Muslim population, by analyzing DNA samples of 100 unrelated Muslim males born in the Cape Metropolitan area. A panel of six mtDNA and eight Y-chromosome SNP markers were screened using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). Overall admixture estimates for the maternal line indicated Asian (0.4168) and African mtDNA (0.4005) as the main contributors. The admixture estimates for the paternal line, however, showed a predominance of the Asian contribution (0.7852). The findings are in accordance with historical data on the origins of the early Cape Muslims.Web of Scienc

Existence of a lens-shaped cluster of surfaces self-shrinking by mean curvature

We rigorously show the existence of a rotationally and centrally symmetric "lens-shaped" cluster of three surfaces, meeting at a smooth common circle, forming equal angles of 120 degrees, self-shrinking under the motion by mean curvature.Comment: 22 pages, 2 figure

Transmission of Mitochondrial DNA Diseases and Ways to Prevent Them

Recent reports of strong selection of mitochondrial DNA (mtDNA) during transmission in animal models of mtDNA disease, and of nuclear transfer in both animal models and humans, have important scientific implications. These are directly applicable to the genetic management of mtDNA disease. The risk that a mitochondrial disorder will be transmitted is difficult to estimate due to heteroplasmy—the existence of normal and mutant mtDNA in the same individual, tissue, or cell. In addition, the mtDNA bottleneck during oogenesis frequently results in dramatic and unpredictable inter-generational fluctuations in the proportions of mutant and wild-type mtDNA. Pre-implantation genetic diagnosis (PGD) for mtDNA disease enables embryos produced by in vitro fertilization (IVF) to be screened for mtDNA mutations. Embryos determined to be at low risk (i.e., those having low mutant mtDNA load) can be preferentially transferred to the uterus with the aim of initiating unaffected pregnancies. New evidence that some types of deleterious mtDNA mutations are eliminated within a few generations suggests that women undergoing PGD have a reasonable chance of generating embryos with a lower mutant load than their own. While nuclear transfer may become an alternative approach in future, there might be more difficulties, ethical as well as technical. This Review outlines the implications of recent advances for genetic management of these potentially devastating disorders

Evidence-Based Management of Hand Eczema

Hand eczema is a common skin disease with a wide variation in morphology and a complex etiology based on endogenous and exogenous factors.The diagnosis of hand eczema is based on patient history, exposure assessment, physical examination, and the results of patch testing. Management of hand eczema starts with education of the patient on the etiology of the disease, and the needed changes in behavior regarding skin care and preventive measures, and avoidance of relevant exposure factors. In many cases, medical treatment is needed for successful management of the disease; use of medication can only be successful with proper education and avoidance of relevant exposure