Treatment outcome in juvenile-onset myasthenia gravis.

Introduction: Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction. Approximately 10%-15% of MG patients have juvenile (<18 years of age) onset. We aimed to assess the clinical course, outcome, and subjectively perceived health status of a cohort of juvenile MG patients.

Are electrophysiological criteria useful in distinguishing childhood demyelinating neuropathies?

Childhood chronic inflammatory demyelinating polyneuropathy (CIDP) needs to be differentiated from hereditary neuropathy. We aimed to validate existing CIDP nerve conduction study (NCS) criteria in a group of children with demyelinating neuropathies of chronic or subacute onset. Retrospective analysis of clinical and NCS results in 18 children with CIDP, 7 with hereditary neuropathy with pressure palsy (HNPP), and 24 with Charcot-Marie-Tooth 1a (CMT1a).

The Frequency of c.550delA Mutation of the CANP3 Gene in the Polish LGMD2A Population.

Background: Limb girdle muscular dystrophy 2A (LGMD2A) is the most frequent LGMD variant in the European population, representing about 40% of LGMD. The c.550delA mutation in the CANP3 (calcium activated neutral protease 3) gene is the most commonly reported mutation in LGMD2A.

Motor unit loss estimation by the multipoint incremental MUNE method in children with spinal muscular atrophy--a preliminary study.

Quantitative EMG reflects denervation of muscles after lower motor neuron degeneration in spinal muscular atrophy (SMA) but does not reflect actual motor unit loss. The aim of our study was to assess the value of the multipoint incremental motor unit number estimation (MUNE) method in the modification by Shefner in estimating motor unit loss in SMA. The number of motor units, the mean amplitude of an average surface-detected single motor unit potential (SMUP), and the amplitude of compound motor action potentials (CMAP) were estimated in 14 children with SMA in the abductor pollicis brevis (ABP).

Novel point mutations in survival motor neuron 1 gene expand the spectrum of phenotypes observed in spinal muscular atrophy patients.

The aim of our study was to identify point mutations in a group of 606 patients diagnosed for spinal muscular atrophy with excluded biallelic loss of the SMN1 gene. Point missense mutations or small deletions in the SMN1 gene were ultimately identified in 18 patients. Six patients were found to have small deletions, the c.

Early-onset facioscapulohumeral muscular dystrophy type 1 with some atypical features.

Facioscapulohumeral muscular dystrophy cases with facial weakness before the age of 5 and signs of shoulder weakness by the age of 10 are defined as early onset. Contraction of the D4Z4 repeat on chromosome 4q35 is causally related to facioscapulohumeral muscular dystrophy type 1, and the residual size of the D4Z4 repeat shows a roughly inverse correlation with the severity of the disease. Contraction of the D4Z4 repeat on chromosome 4q35 is believed to induce a local change in chromatin structure and consequent transcriptional deregulation of 4qter genes.

Clinical, electrophysiological, and molecular findings in early onset hereditary neuropathy with liability to pressure palsy.

Introduction: The first episode of hereditary neuropathy with liability to pressure palsy (HNPP) in childhood is rare.

Methods: We analyzed retrospectively the data of 7 patients with a deletion in PMP22 and onset of symptoms before age 18 years. Direct sequencing of the LITAF (lipopolysaccharide-induced tumor necrosis factor) gene was performed in patients and family members.

Carpal tunnel syndrome in children.

Carpal tunnel syndrome rarely occurs in children. We retrospectively analyzed clinical data of 11 patients aged 5-17 diagnosed with carpal tunnel syndrome at a single pediatric neuromuscular center. Nerve conduction studies were performed according to the American Association of Electrodiagnostic Medicine recommendations.

Two pathogenic mutations located within the 5'-regulatory sequence of the GJB1 gene affecting initiation of transcription and translation.

In contrast to mutations in the coding sequences of a genes involved in the pathogenesis of Charcot-Marie-Tooth disease (CMT), little is known about CMT phenotypes resulting from a DNA variants located in regulatory sequences of a given " CMT gene". Charcot-Marie-Tooth type X1 disease (CMTX1) is caused by mutations in the GJB1 gene coding for an ion channel known as connexin, with a molecular mass of 32 kDa (Cx32). Only 0.

L239F founder mutation in GDAP1 is associated with a mild Charcot-Marie-Tooth type 4C4 (CMT4C4) phenotype.

Over 40 mutations in the GDAP1 gene have been shown to segregate with Charcot-Marie-Tooth disease (CMT). Among these, only two mutations, i.e.

[Detection of rare mutations in the dystrophin gene].

Introduction: Duchenne/Becker muscular dystrophies (DMD/BMD) are allelic X-linked, recessive proximal muscle disorders, caused by mutations in the dystrophin gene located in Xp21. DMD occurs with the incidence 1:3500, BMD with the incidence of 1:18,500 new-born males. Approximately about 60% of mutations in the dystrophin gene are deletions, 10%--duplications and 30%--point mutations.

A patient with both Charcot-Marie-Tooth disease (CMT 1A) and mild spinal muscular atrophy (SMA 3).

In the present study, we report a single Polish SMA family in which the 17p11.2-p12 duplication causative for the Charcot-Marie-Tooth type 1A disease (CMT1A) was found in addition to a deletion of exons 7 and 8 of the SMN1 gene. A patient harboring both SMA and CMT1A mutations manifested with SMA3 phenotype and foot deformity.

Multi-minicore myopathy: a clinical and histopathological study of 17 cases.

Multi-minicore disease (MmD) is a congenital myopathy morphologically defined by the multifocal lack of oxidative activity on light microscopy (LM) and multiple small zones of sarcomeric disorganization on electron microscopy (EM) as the main findings in muscle biopsy. We report on clinical and pathomorphological features of 17 patients diagnosed with multi-minicore myopathy at our department. Clinically, axial and proximal muscle weakness was the predominant distinguishing feature.

Is a novel I214M substitution in the NEFL gene a cause of Charcot-Marie-Tooth disease? Functional analysis using cell culture models.

Recent studies have shown that mutations in neurofilament light subunit gene (NEFL) cause Charcot-Marie-Tooth (CMT) disease. Since the first description of the Gln333Pro mutation in the NEFL gene, 10 pathogenic mutations in the NEFL gene have been reported in patients affected with CMT disease. We report a novel I214M amino acid substitution in the NEFL gene in two unrelated patients affected with CMT.

MFN2 mutation distribution and genotype/phenotype correlation in Charcot-Marie-Tooth type 2.

Mutations in mitofusin 2 (MFN2) have been reported in Charcot-Marie-Tooth type 2 (CMT2) families. To study the distribution of mutations in MFN2 we screened 323 families and isolated patients with distinct CMT phenotypes. In 29 probands, we identified 22 distinct MFN2 mutations, and 14 of these mutations have not been reported before.

A novel Met116Thr mutation in the GDAP1 gene in a Polish family with the axonal recessive Charcot-Marie-Tooth type 4 disease.

Mutations in the gene coding for ganglioside-induced differentiation-associated protein-1 (GDAP1), which maps to chromosome 8q21, have been described in families with autosomal recessive Charcot-Marie-Tooth disease (CMT4A). Interestingly, some mutations in the GDAP1 gene have been reported in the demyelinating form of CMT1 disease, whereas others were found in patients with the axonal type of CMT disease. So far, 23 mutations in the GDAP1 gene have been reported in patients of different ethnic origins.

Application of a rapid non-invasive technique in the molecular diagnosis of spinal muscular atrophy (SMA).

Background And Purpose: Proximal spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by mutations of the SMN1 gene. The most frequent mutation is biallelic deletion of exon 7 of the SMN1 gene. A small percentage of SMA patients present compound heterozygosity with a point mutation on one allele and deletion on the other.

[Genetic investigations in facioscapulohumeral muscular dystrophy: a preliminary report].

Facioscapulohumeral muscular dystrophy (FSHD) is a primary muscle disorder with autosomal dominant inheritance. FSHD was mapped to chromosome 4 locus q35, but the gene is not yet known. It is characterised by progressive, often asymmetric, selective muscular weakness and great clinical variability.

Early onset Charcot-Marie-Tooth type 1B disease caused by a novel Leu190fs mutation in the myelin protein zero gene.

The spectrum of Charcot-Marie-Tooth (CMT) phenotypes segregating with mutations in the Myelin Protein Zero (MPZ) gene is wide and ranges from congenital hypomyelinating neuropathy (CHN) through demyelinating form of CMT to the axonal type of CMT disease. Within 94 MPZ gene mutations reported up to now, only a few were identified in the exon 4 of the MPZ gene. In this study we have identified a novel Leu190fs mutation in the MPZ gene.

Different expressions of X-linked cardiomyopathy in monozygotic triplets with Becker's dystrophy.

Cardiac involvement is common in skeletal muscles disorders associated with dystrophin defect. It has been suggested however, that X-linked dilated cardiomyopathies with minimal or absent skeletal disease are distinct entities, resulting from mutations in cardiac-specific regions of dystrophin gene. This study presents a unique observation of phenotypic variability in monozygotic triplets with Becker's muscular dystrophy.

[Identification of T274I mutation in the SMN1 gene in a patient with spinal muscular atrophy].

Proximal spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder characterised by degeneration of motor neurones in the spinal cord. The symptoms of the disease are determinated by mutations of SMN1 gene. About 98% of SMA patients show homozygous absence of exon 7 SMN1 gene, the rest carry small intragenic mutations.

[Charcot-Marie Tooth type X (CMTX) disease: clinical and genetic characteristics of eleven patients].

Charcot-Marie-Tooth type X disease (CMTX) is the second most frequent inherited neuropathy, after CMT1A type associated with 17p11.2-p12 duplication. CMTX is inherited as X dominant trait and is caused by point mutations in Cx32 gene.