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Charcot‑Marie‑Tooth disease (CMT) is the most common inherited neurological disorder of the peripheral nervous system. The major subtype, CMT type 1A (CMT1A), accounts for ~40% of CMT cases and is characterized by distal muscle atrophy and gait disturbances. Short hairpin (sh) RNA sequences are potentially advantageous therapeutic tools for distal muscle atrophy‑induced gait disturbance. Therefore, the current study focused on the effects of an optimal shRNA injection using the myostatin (mstn) gene inhibition system. shLenti‑Mstn A demonstrated significant suppression of endogenous mstn gene expression (>40%) via RT‑qPCR following direct injection into the gastrocnemius and rectus femoris of the hind limb in C22 mice. The results also reported that shLenti‑Mstn A treatment increased muscle mass and size of the hind limbs compared with mock‑treated mice via measurement of the mass of injected muscles and magnetic resonance imaging study. Furthermore, electrophysiological measurement using a Nicolet Viking Quest device revealed significantly improved compound muscle action potential (CMAP) in shLenti‑Mstn A‑treated mice compared with the mock group (P<0.05) whereas nerve conduction velocity (NCV) showed no difference between groups. The shLenti‑Mstn A treatment directly affected increased muscle regeneration, including mass and size, but not regeneration of peripheral nerve. Additionally, shLenti‑Mstn A treatment significantly enhanced mobility, including locomotor coordination (P<0.01) and grip strength of the hindlimbs (P<0.01). Furthermore, MotoRater analysis using real‑time recording with a high‑speed camera revealed that shLenti‑Mstn‑treated mice exhibited an improved walking pattern in terms of step length, base support and duty factor compared with the mock group. It was hypothesized that treatment with shLenti‑Mstn A may provide a novel therapeutic strategy for improving gait in patients with CMT1A. [ABSTRACT FROM AUTHOR]

Mutations in the Dynactin 1 (DCTN1) gene have been demonstrated to result in various neurodegenerative diseases, including distal hereditary motor neuropathy type 7B (dHMN7B), Perry syndrome, amyotrophic lateral sclerosis and amyotrophic lateral sclerosis-frontotemporal dementia. However, since the first dHMN7B patient with a DCTN1 mutation was described in 2003, to the best of our knowledge no further cases have been reported. In the present study, the DCTN1 p.G59S mutation was identified in two unrelated families from a total of 24 Korean families with dHMN, by whole exome sequencing. Codon 59 appears to be the mutational hot spot in the DCTN1 gene, as all described dHMN7B patients to date have harbored an identical p.G59S mutation. The families of the present study with the DCTN1 mutation had a milder disease with a later onset compared with the previously described patients. No affected family members exhibited facial muscle weakness or bulbar involvement. One family member demonstrated vocal cord palsy as the initial sign of disease; however, in the other family hand muscle weakness was the first major symptom. No affected patients demonstrated sensory loss or upper motor neuron involvements. Although this is only the second report of dHMN7B resulting from a DCTN1 mutation, the frequency of the DCTN1 mutation was not low in the Korean population examined, and clinical heterogeneities were observed in patients with the DCTN1 mutation. Therefore, it may be beneficial to screen all dHMN patients for the DCTN1 mutation. [ABSTRACT FROM AUTHOR]

Hereditary sensory and autonomic neuropathy type I (HSAN I) is an autosomal dominant disease characterized by prominent sensory impairment, resulting in foot ulcers or amputations and has a juvenile to adult onset. The major underlying causes of HSAN I are mutations in SPTLC1, which encodes the first subunit of serine palmitoyltransferase (SPT). To date, there have been no reports with regard to an HSAN patient of Korean origin. In this report we discussed an HSAN I patient with a missense mutation in SPTLC1 (c.992C>T: p.S331F). The patient had noticed frequent falls, lower leg weakness and hand tremors at age five. The patient also presented with foot ulcers, muscle hypotrophy, cataracts, hoarseness, vocal cord palsy and respiratory difficulties and succumbed to the condition at the age of 28 years. In accordance with previous reports, a mutation in Ser331 in the present patient was associated with early-onset and a severe phenotype. Therefore, Ser331 in SPTLC1 is a crucial amino acid, which characterizes the HSAN I phenotype. [ABSTRACT FROM AUTHOR]