Effects of HMG CoA reductase (HMGCR) deficiency on skeletal muscle development.

Pathogenic variants in HMGCR were recently linked to a limb-girdle muscular dystrophy (LGMD) phenotype. The protein product HMG CoA reductase (HMGCR) catalyzes a key component of the cholesterol synthesis pathway. The two other muscle diseases associated with HMGCR, statin-associated myopathy (SAM) and autoimmune anti-HMGCR myopathy, are not inherited in a Mendelian pattern.

High resolution kinematic approach for quantifying impaired mobility of dystrophic zebrafish larvae.

Dystrophin-deficient zebrafish larvae are a small, genetically tractable vertebrate model of Duchenne muscular dystrophy well suited for early stage therapeutic development. However, current approaches for evaluating their impaired mobility, a physiologically relevant therapeutic target, are characterized by low resolution and high variability. To address this, we used high speed videography and deep learning-based markerless motion capture to develop linked-segment models of larval escape response (ER) swimming.

Dominant stop-loss HNRNPA1 variants in juvenile-onset myopathy.

Introduction/aims: Heterogeneous nuclear ribonucleoprotein A1 is involved in nucleic acid homeostatic functions. The encoding gene HNRNPA1 has been associated with several neuromuscular disorders including an amyotrophic lateral sclerosis-like phenotype, distal hereditary motor neuropathy, multisystem proteinopathy, and various myopathies. We report two unrelated individuals with monoallelic stop loss variants affecting the same codon of HNRNPA1.