Muscular dystrophy overview: genetics and diagnosis

Epigenetics and Human Disease

Genetic causes for human disorders are being discovered at an unprecedented pace. A growing subclass of disease-causing mutations involves changes in the epigenome or in the abundance and activity of proteins that regulate chromatin structure. This article focuses on research that has uncovered human diseases that stem from such epigenetic deregulation. Disease may be caused by direct changes in epigenetic marks, such as DNA methylation, commonly found to affect imprinted gene regulation. Also described are disease-causing genetic mutations in epigenetic modifiers that either affect chromatin in trans or have a cis effect in altering chromatin configuration.

Oral health considerations in muscular dystrophies

Muscular dystrophies (MD) are a heterogeneous group of inherited neuromuscular disorders characterized by muscle necrosis and progressive muscle weakness. It is important for oral healthcare providers to be familiar with MD as special considerations are necessary to provide appropriate and safe dental care for these medically complex patients. This article briefly reviews the more common types of MD, namely, Duchenne MD, Becker MD, Emery-Dreifuss MD, facioscapulo-humeral MD, limb-girdle MD, oculopharyngeal MD, and myotonic dystrophy. Aspects of their epidemiology, pathophysiology, clinical presentation, diagnosis, and medical management as well as oral health considerations are discussed.

Nephrolithiasis in patients with duchenne muscular dystrophy

OBJECTIVES

To present the first series of patients with Duchenne muscular dystrophy (DMD) and nephrolithiasis.

METHODS

A retrospective chart review was done to identify patients with DMD who were referred for urologic consultation because of nephrolithiasis from June 2004 to April 2006.

RESULTS

Four patients were identified with DMD and nephrolithiasis. Of the 4 patients, 2 underwent treatment, and their stones were obtained for analysis. The other 2 patients had stones diagnosed by computed tomography. Their stones were passed but not retrieved. Stone analysis for the available patients revealed a mixed calcareous composition. All 4 patients had had a relatively small stone burden. The patients ranged in age from 18 to 31 years.

CONCLUSIONS

Stone disease appears to have many of the same characteristics in patients with DMD as it does in the general population. Risk factors, including immobilization and corticosteroid use, are present. Additional studies are needed before conclusions can be made regarding the associations between DMD and nephrolithiasis.

The interface of genomic technologies and nursing

PURPOSES

(a) to summarize views of the interface of technology, genomic technology, and nursing; (b) provide an overview of current and emerging genomic technologies; (c) present clinical exemplars of uses of genomic technology in two disease conditions; and (d) list genomic-focused nursing research on genomic technologies.

ORGANIZING FRAMEWORK

A discussion of genomic technology in the context of nurses' views of technology, the importance of genomic technology for nurses, linking the central dogma of molecular biology to state-of-the-art tests and assays, and nurses' current use of technologies.

CONCLUSIONS

Human genome discoveries will continue to be an integral part of disease prevention, diagnosis, treatment, and management. These discoveries also have the potential for being integrated into nursing science. Genomic technologies are becoming a driving force in patient management, so that nurses will be unable to provide quality care without knowledge of the types of genomic technologies, the rationale for their use, and the possible sequelae that can result from genetic diagnosis or treatment. Many nurses already are using genomic technologies to conduct genomic-focused nursing research. The biobehavioral nature of much of this research further indicates the important contributions of nurses in genomics.

The heart in muscular dystrophy

Pediatricians and other healthcare professionals need to be alert to the presence and progression of cardiac involvement in patients with MD. The signs and symptoms of cardiac involvement may be minimal, necessitating careful interval history, physical examination, and noninvasive cardiac testing. Available treatment strategies may reduce disease morbidity and mortality. It is reasonable to expect that a child who has skeletal muscle weakness from MD may have cardiac involvement, even if it is subclinical. Treatment of the muscular dystrophies through genetic engineering is a future dream. However, the improvements in clinical care, evaluation and treatment standards, and multidisciplinary supportive care are able to benefit the current generation of children.

Dystroglycan: important player in skeletal muscle and beyond

Dystroglycan is a transmembrane protein that connects the extracellular matrix to the cytoskeleton. Given the ubiquitous tissue expression of dystroglycan, different functional roles in various organ systems have been characterized during the past decade. More recently, aberrant glycosylation of dystroglycan has been identified as a novel pathogenetic mechanism in several forms of congenital and late onset muscular dystrophy syndromes. The current review summarizes the recent scientific achievements as they relate to the function of dystroglycan under normal and pathophysiological conditions.