Nemaline Myopathy Presenting as Adult-onset Distal Myopathy / 대한임상신경생리학회지

No abstract available.

Clinical, myopathological and genetic research of a patient with distal myopathy caused by caveolin-3 deficiency / 中华神经科杂志

Objective To report the clinical,myopathological and genetic features of a patient with distal myopathy caused by caveolin-3 (CAV3) deficiency.Methods The patient was a 27-year-old female.She had an onset symptom of asymmetric lower extremities weakness.The proximal limb-girdle muscles were involved subsequently.Clinical data of this patient were collected.The leg muscle magnetic resonance imaging (MRI) and an open biopsy of left tibialis anterior muscle were performed.In addition to histological,enzyme histochemical staining and ultrastructural examination,immunohistochemical staining with antibody against CAV3 was done.CAV3 gene was analyzed in the patient and her parents.Results Tl-weighted enhanced skeletal muscle MRI of the lower limbs showed the abnormal signal in distal and proximal muscles.Muscle biopsy showed moderate dystrophic changes and immunostaining for CAV3 showed reduced plasmalemma in the muscle fibers.Gene analysis disclosed a heterozygous c.136G ＞ A (p.Ala46Thr)mutation in the CAV3 gene,and the patient's parents did not have this mutation.Conclusions We report a distal myopathy case caused by c.136G ＞ A (p.Ala46Thr) mutation in the CAV3 gene,who had an onset symptom of asymmetric lower extremities weakness.The proximal limb-girdal muscles were also involved.This would help clinical doctors to know more about this rare myopathy.

Affected muscle fibers in Nonaka myopathy with endoplasmic reticulum stress / 中华神经科杂志

ObjectiveTo investigate the characteristic of pathology in Chinese patients with Nonaka myopathy.MethodsThirteen patients (7 males and 6 females) diagnosed with Nonaka myopathy in our laboratory from January 2002 to March 2011 were included in this study.Their mean age was 39.5 years old and the mean duration of illness was 4.15 years.The most common symptoms were weakness of raising feet with sparing of quadriceps femoris muscles in the early stage of disease.One patient presented the initial symptoms of upper limb weakness. Muscles biopsies were obtained from all these 13 patients. Histology study including immunohistochemical (IHC) staining with antibody against amyloid 3,phosphorylated tau protein,ubiquitin,glucose-regulated protein of molecular weight 78 000(GRP78),calnexin,caspase-12and Bax were performed.Skeletal muscle samples from 3 chronic fatigue syndrome patients,2 myofibrillar myopathy patients were used for control in the IHC staining. All coding exons of uridinediphospho-N-acetylglucosamine 2-epimerase gene were directly sequenced in genomic DNA from these patients.Results The main pathological changes of tibialis anterior muscle in 12 cases were muscle dystrophy with rimmed vacuoles.The rimmed vacuoles were positive for anti-β-amyloid,tau protein and ubiquitin in IHC studies.In the atrophy fibers,IHC showed the increased expression of endoplasmic reticulum stress related proteins GRP78 and calnexin,and apoptosis proteins of caspase-12 and Bax.ConclusionsThere is accumulation of abnormal proteins in muscle fibers in Chinese patients with Nonaka myopahty.These proteins may stimulate endoplasmic reticulum stress and apoptosis,which may be a mechanism responsible for muscle damage.

Autosomal Dominant Centronuclear Myopathy with Unique Clinical Presentations

Centronuclear myopathies are clinically and genetically heterogenous diseases with common histological findings, namely, centrally located nuclei in muscle fibers with a predominance and hypotrophy of type 1 fibers. We describe two cases from one family with autosomal dominant centronuclear myopathy with unusual clinical features that had initially suggested distal myopathy. Clinically, the patients presented with muscle weakness and atrophy localized mainly to the posterior compartment of the distal lower extremities. Magnetic resonance imaging revealed predominant atrophy and fatty changes of bilateral gastrocnemius and soleus muscles. This report demonstrates the expanding clinical heterogeneity of autosomal dominant centronuclear myopathy.

Clinical and Genetic Analysis of Korean Patients with Miyoshi Myopathy: Identification of Three Novel Mutations in the DYSF Gene

Miyoshi myopathy (MM) is an autosomal recessive distal muscular dystrophy caused by mutations in the dysferlin gene (DYSF) on chromosome 2p13. Although MM patients and their mutations in the DYSF gene have been found from all over the world, there is only one report of genetically confirmed case of MM in Korea. Recently, we encountered three unrelated Korean patients with MM and two of them have previously been considered as having a type of inflammatory myopathy. The clinical and laboratory evaluation showed typical features of muscle involvement in MM in all patients but one patient initially had moderate proximal muscle involvement and another showed incomplete quadriparesis with rapid progression. Direct sequencing analysis of the DYSF gene revealed that each patient had compound heterozygous mutations (Gln832X and Trp992Arg, Gln832X and Trp999Cys, and Lys1103X and Ile1401HisfsX8, respectively) among which three were novel. Although MM has been thought to be quite rare in Korea, it should be considered in a differential diagnosis of patients exhibiting distal myopathy.