NAD dyshomeostasis in RYR1-related myopathies.

Background: Pathogenic variants in RYR1 cause a spectrum of rare congenital myopathies associated with intracellular calcium dysregulation. Glutathione redox imbalance has been reported in several Ryr1 disease model systems and clinical studies. NAD and NADP are essential cofactors in cellular metabolism and redox homeostasis.

Rycal S48168 (ARM210) for -related myopathies: a phase one, open-label, dose-escalation trial.

Background: -related myopathies (-RM) are caused by pathogenic variants in the gene which encodes the type 1 ryanodine receptor (RyR1). RyR1 is the sarcoplasmic reticulum (SR) calcium release channel that mediates excitation-contraction coupling in skeletal muscle. RyR1 sub-conductance, SR calcium leak, reduced RyR1 expression, and oxidative stress often contribute to -RM pathogenesis.

Ryanodine Receptor 1-Related Myopathies: Quantification of Intramuscular Fatty Infiltration from T1-Weighted MRI.

Background: Ryanodine receptor 1-related myopathy (RYR1-RM) can present with a selective pattern and gradient of intramuscular fatty infiltration (IMFI) on magnetic resonance imaging (MRI).

Objective: To demonstrate an automated protocol for quantification of IMFI in the lower extremity muscles of individuals with RYR1-RM using T1-weighted MRI and to examine the relationships of IMFI with motor function and clinical severity.

Methods: Axial images of the lower extremity muscles were acquired by T1-weighted fast spin-echo and short tau inversion recovery (STIR) sequences.

Ryanodine receptor 1-related disorders: an historical perspective and proposal for a unified nomenclature.

The RYR1 gene, which encodes the sarcoplasmic reticulum calcium release channel or type 1 ryanodine receptor (RyR1) of skeletal muscle, was sequenced in 1988 and RYR1 variations that impair calcium homeostasis and increase susceptibility to malignant hyperthermia were first identified in 1991. Since then, RYR1-related myopathies (RYR1-RM) have been described as rare, histopathologically and clinically heterogeneous, and slowly progressive neuromuscular disorders. RYR1 variants can lead to dysfunctional RyR1-mediated calcium release, malignant hyperthermia susceptibility, elevated oxidative stress, deleterious post-translational modifications, and decreased RyR1 expression.

Assessing Motor Function in Congenital Muscular Dystrophy Patients Using Accelerometry.

Background: When tested in a controlled clinic environment, individuals with neuromuscular-related symptoms may complete motor tasks within normal predicted ranges. However, measuring activity at home may better reflect typical motor performance. The accuracy of accelerometry measurements in individuals with congenital muscular dystrophy (CMD) is unknown.

Preclinical model systems of ryanodine receptor 1-related myopathies and malignant hyperthermia: a comprehensive scoping review of works published 1990-2019.

Background: Pathogenic variations in the gene encoding the skeletal muscle ryanodine receptor (RyR1) are associated with malignant hyperthermia (MH) susceptibility, a life-threatening hypermetabolic condition and RYR1-related myopathies (RYR1-RM), a spectrum of rare neuromuscular disorders. In RYR1-RM, intracellular calcium dysregulation, post-translational modifications, and decreased protein expression lead to a heterogenous clinical presentation including proximal muscle weakness, contractures, scoliosis, respiratory insufficiency, and ophthalmoplegia. Preclinical model systems of RYR1-RM and MH have been developed to better understand underlying pathomechanisms and test potential therapeutics.

Randomized controlled trial of -acetylcysteine therapy for -related myopathies.

Objective: To investigate the efficacy of -acetylcysteine (NAC) for decreasing elevated oxidative stress and increasing physical endurance in individuals with ryanodine receptor 1-related myopathies (-RM).

Methods: In this 6-month natural history assessment (n = 37) followed by a randomized, double-blinded, placebo-controlled trial, 33 eligible participants were block-randomized (1:1) to receive NAC (n = 16) or placebo (n = 17), orally for 6 months (adult dose 2,700 mg/d; pediatric dose 30 mg/kg/d). The primary endpoint was urine 15-F2t isoprostane concentration and the clinically meaningful co-primary endpoint was 6-minute walk test (6MWT) distance.

Reliability and Validity of Self-Report Questionnaires as Indicators of Fatigue in RYR1-Related Disorders.

Background: RYR1-related disorders (RYR1-RD), are a spectrum of genetic neuromuscular disorders. Affected individuals frequently experience fatigue yet appropriate tools to assess RYR1-RD-associated fatigue remain underdeveloped.

Objective: This study assessed the reliability and validity of two self-report questionnaires, the multidimensional fatigue inventory (MFI-20) and adult/pediatric functional assessment of chronic illness-fatigue (FACIT-F/Peds-FACIT-F) as potential fatigue measures in RYR1-RD affected individuals.

Ryanodine Receptor 1-Related Myopathies: Diagnostic and Therapeutic Approaches.

Ryanodine receptor type 1-related myopathies (RYR1-RM) are the most common class of congenital myopathies. Historically, RYR1-RM classification and diagnosis have been guided by histopathologic findings on muscle biopsy. Main histological subtypes of RYR1-RM include central core disease, multiminicore disease, core-rod myopathy, centronuclear myopathy, and congenital fiber-type disproportion.

Correlation of phenotype with genotype and protein structure in RYR1-related disorders.

Variants in the skeletal muscle ryanodine receptor 1 gene (RYR1) result in a spectrum of RYR1-related disorders. Presentation during infancy is typical and ranges from delayed motor milestones and proximal muscle weakness to severe respiratory impairment and ophthalmoplegia. We aimed to elucidate correlations between genotype, protein structure and clinical phenotype in this rare disease population.

Health behaviors among unaffected participants following receipt of variants of uncertain significance in cardiomyopathy-associated genes.

Purpose: Studies on returning variants of uncertain significance (VUS) results have predominantly included patients with a personal or family history of cancer and cancer-associated gene VUS. This study examined health behaviors among participants with cardiomyopathy-associated gene VUS, but without a personal history of cardiomyopathy.

Methods: Sixty-eight eligible participants without apparent cardiomyopathy but with VUS in cardiomyopathy-associated genes completed a survey of health behaviors, disclosure, distress, uncertainty, positive experiences, decisional conflict, and perceived value.

Novel Variants in Individuals with -Related Congenital Myopathies: Genetic, Laboratory, and Clinical Findings.

The ryanodine receptor 1-related congenital myopathies (-RM) comprise a spectrum of slow, rare neuromuscular diseases. Affected individuals present with a mild-to-severe symptomatology ranging from proximal muscle weakness, hypotonia and joint contractures to scoliosis, ophthalmoplegia, and respiratory involvement. Although there is currently no FDA-approved treatment for RM, our group recently conducted the first clinical trial in this patient population (NCT02362425).

The relationships among coping strategies, religious coping, and spirituality in African American women with breast cancer receiving chemotherapy.

Purpose/objectives: To (a) examine coping capacity, psychological distress, spiritual well-being, positive and negative religious coping, and coping strategies among African American (AA) women with breast cancer, and (b) explore relationships among these variables to enhance an already tested comprehensive coping strategy program (CCSP) intervention for AA women with breast cancer (CCSP-AA).

Design: Descriptive-correlational.

Setting: Comprehensive cancer center in Maryland.