Miyoshi Muscular Dystrophy Due to Novel Splice Site Variants in DYSF Gene.

Dysferlinopathies are a group of phenotypically heterogeneous disorders caused by pathogenic variants in the DYSF (DYStrophy-associated Fer-1-like) gene encoding dysferlin. The phenotypic spectrum includes Miyoshi muscular dystrophy (MMD), limb-girdle muscular dystrophy type R2, distal myopathy with anterior tibial onset, and isolated hyperCKemia. MMD is characterized by muscle weakness and atrophy predominantly affecting the calf muscles with symptoms onset between 14 and 40 years of age. There is no clear phenotype - genotype correlation for dysferlinopathy. We describe a 15-year-old girl who presented with a phenotype consistent with MMD. However, she was initially treated for presumed polymyositis without improvement. Subsequent genetic testing revealed two novel variants in DYSF: c.3225dup (p.Gly1076Trpfs*38) in exon 30 and c.3349-2A > G (Splice acceptor) in intron 30. No dysferlin was detected in a muscle biopsy using immunostains and western blots, a result consistent with dysferlinopathy that supports the pathogenicity of the DYSF variants.

The epidemiology of injury and illness at the Vitality Netball World Cup 2019: an observational study.

BACKGROUND: Netball is a physical game with sudden direction changes, decelerations, jumping and landing, stop/start maneuvers and restrictive footwork rules exposing players to injury. Close contact play and shared facilities during tournaments, increase illness risk.Objective: To describe incidence, period prevalence, types and severity of injuries and illnesses during the 10-day Vitality Netball World Cup 2019 (NWC).Methods: All players from 16 teams consented (n = 192). Medical staff recorded injuries (840 exposure hours), illnesses (1440 player-days) and time-loss. Main outcome measures included incidence (I) calculated as injury/1000 player-hours and illness/1000 player-days, period prevalence (PP) and severity (time-loss) of all match injuries and illnesses. RESULTS: 39 players sustained 46 match injuries (I = 54.76; PP = 20.31%). Lower limb injuries (I = 29.76), specifically the ankle (I = 13.10) were most common with lateral ankle ligament sprains the highest (I = 17.39). Contact injuries (I = 40.48) significantly exceeded non-contact injuries (I = 14.29; p = 0.0124). Center players sustained most injuries (n = 12; 26%; I = 14.29), followed by goalkeepers (n = 10; 22%; I = 11.90) and goal defenders (n = 8; 17%; I = 9.52). Injuries occurred in almost 50% of matches, and 67% did not result in time-loss. Time-loss injuries (n = 14; 33%) were most frequent in the lower limb (n = 10; 71%) specifically involved lateral ankle ligaments (n = 4; 29%), attributable to contact (n = 11; 79%) and mostly implicated center players and goal defenders (n = 4 each; 29% each). 11 players contracted 11 illnesses (I = 7.64; PP = 5.72%) with respiratory tract illness contributing 36%. Most illnesses did not result in time-loss (91%). CONCLUSION: This is the first study reporting injury and illness during an NWC. Contact was the main mechanism of injury, and 2/3 of injuries did not result in time-loss. The ankle is most commonly injured and center players sustain most injuries. Non-respiratory system disease was most frequent, but upper respiratory tract infection remains the most common diagnosis. Targeted surveillance studies using similar methodology are required to develop injury and illness preventative strategies in elite netball.

Effect of load during electrical stimulation training in spinal cord injury.

Electrical stimulation training is known to alter skeletal muscle characteristics after a spinal cord injury, but the effect of load on optimizing the training protocol has not been fully investigated. This study investigated two electrical-stimulation training regimes with different loads on intramuscular parameters of the paralyzed lower limbs. Six paraplegic individuals with a spinal cord injury underwent electrical stimulation training (45 min daily for 3 days per week for 10 weeks). One leg was trained statically with load, and the contralateral leg was trained dynamically with minimal load. Isometric force assessed with 35-HZ stimuli increased significantly in both legs from baseline, with the static-trained leg also being significantly higher than the dynamic-trained leg. The vastus lateralis muscle of the statically trained leg showed a significant increase in type I fibers, fiber cross-sectional area, capillary-to-fiber ratio, and citrate synthase activity when compared to both baseline and the dynamically trained leg. Relative oxygenation of the vastus lateralis muscle as determined by near infrared spectroscopy was also significantly greater after static training. This study indicates that the load that is applied to paralyzed muscle during an electrical stimulation training program is an important factor in determining the amount of muscle adaptation that can be achieved.